Food as Medicine: Healthful Eating for Healthy Living

One of the best-kept secrets in healthcare is that “something as simple as the food on your plate can truly be medicine.”

Introduction

Over the centuries food has been a central element in many traditional forms of medicine, which treated food as medicine until its role in curative medicine began to decline during the last century. The role of healthful eating in both preventative and therapeutic medicine has been documented in medical texts dating as far back as 500 BC.

This popular phrase attributed to Hippocrates (460 BC to 370 BC) emphasizes the importance of healthy diets to prevent or cure disease. Ayurveda, one of the oldest healthcare systems that originated over three millennia ago in the Indian subcontinent, offers extensive insights about food and health based on certain unique conceptual as well as theoretical positions.

Healthful eating: Association of sub-optimal diets with disease

In my post, Chronic Diseases: the Silent Killers, I had highlighted that lifestyle-related chronic diseases are the leading killers globally, accounting for 70% of all deaths globally, in 2015. In another related post, Lifestyle-related Diseases: the Biggest Man-Made Disaster, I had discussed why these diseases can be labelled as man-made disasters. Here I had highlighted that bad lifestyle choices, including unhealthy diets, contribute to more than two-thirds of all major lifestyle-related diseases.

Several studies have examined the association of suboptimal diets with various lifestyle-related chronic diseases. A few of these will be discussed here briefly. A study titled ‘Health effects of dietary risks in 195 countries, 1990-2017: a systematic analysis’ for the global burden of disease study 2017’ published in the journal The Lancet in April 2019, evaluated the consumption of major foods and nutrients across 195 countries to quantify the impact of their suboptimal intake on non-communicable diseases (NCDs) mortality and morbidity. The study found that globally, consumption of nearly all healthy foods and nutrients was suboptimal in 2017. The study found that globally in 2017, dietary risks were responsible for 11 million deaths (22% of all deaths among adults) and 255 million disability-adjusted life-years (DALYs) (15% of all DALYs among adults). Cardiovascular disease was the leading cause of diet-related deaths (10 million deaths) and DALYs (207 million DALYs), followed by cancers (9,13,090 deaths and 20 million DALYs) and type 2 diabetes (3,38,714 deaths and 24 million DALYs). More than 5 million diet-related deaths (45% of total diet-related deaths) and 177 million diet-related DALYs (70% of total diet-related DALYs) occurred among adults aged younger than 70 years.

Another important finding of the study was that a small number of dietary risks had a large impact on health outcomes. In 2017, more than half of diet-related deaths and two-thirds of diet-related DALYs were attributable to high intake of sodium (3 million deaths and 70 million DALYs), low intake of whole grains (3 million deaths and 82 million DALYs), and low intake of fruits (2 million deaths and 65 million DALYs). The study further showed that a suboptimal diet is responsible for more deaths than any other risks globally, including tobacco smoking, highlighting the urgent need for improving human diet across nations. The study found that improvement of diet could potentially prevent one in every five deaths globally.

Another study titled ‘Global, regional, and national burden of ischemic heart disease and its attributable risk factors, 1990-2017: results from the Global Burden of Diseases Study 2017’ published in the European Heart Journal – Quality of Care and Clinical Outcomes in Oct 2020, estimated the burden and risk factors for ischaemic heart disease (IHD) in 195 countries and territories from 1990-2017, using data from the Global Burden of Diseases Study 2017 (GBD 2017). The study found that in 2017, IHD affected 126.5 million people worldwide, an increase of 74.9% compared with 1990. Among all potentially modifiable risk factors quantified in GBD 2017, age-standardised IHD deaths worldwide in 2017 were primarily attributable to dietary risks (69.2%), followed by high systolic blood pressure (54.4%), high LDL cholesterol (41.9%), high fasting plasma glucose (25.5%), tobacco use (20.6%) and high body mass index (17.6%) (the cumulative impact of risk factors is not the simple addition of their individual contributions as the risk factors may overlap). Accordingly, the study suggested that multiple efforts are still needed to create healthy lifestyles, including healthful eating, combined with pharmacological treatment of these risk factors.

Another important study examined the association of specific nutrients/foods to various lifestyle-related chronic diseases. The research article titled ‘Association Between Dietary Factors and Mortality From Heart Disease, Stroke, and Type 2 Diabetes in the United States’ published in the journal JAMA in Mar 2017, estimated associations of intake of 10 specific dietary factors with mortality due to heart disease, stroke, and type 2 diabetes (cardiometabolic mortality) among US adults. The study found that 45.4% of deaths from heart disease and stroke were directly attributable to sub-optimal diets. The largest numbers of estimated diet-related cardiometabolic deaths were related to high sodium (9.5% of all cardiometabolic deaths), low nuts/seeds (8.5%), high processed meats (8.2%), low seafood omega-3 fats (7.8%), low vegetables (7.6%), low fruits (7.5%) and high sugar-sweetened beverages (7.4%).

These findings were further supplemented by another research study titled ‘The State of US Health, 1990-2016: Burden of Diseases, Injuries, and Risk Factors Among US States’ published in the journal JAMA in Apr 2018. The study found that suboptimal diet is actually the number 1 risk factor (out of the 17 leading risk factors in the US in 2016) for dying of a chronic disease; even greater than tobacco use at the population level. In 2016, dietary risks accounted for 5,29,299 deaths, with 83.9% of these deaths due to cardiovascular diseases, and the remainder due to a combination of neoplasms and diabetes, and to urogenital, blood, and endocrine diseases. For disability-adjusted life years (DALYs), the suboptimal diet was the third leading cause, marginally behind tobacco use and high body mass index.

On the other hand, studies have examined the beneficial effects of certain dietary patterns on disease prevention. Adventist Health Study-2 (AHS-2) with 96,000 Adventist participants in the US and Canada, is one of the largest and most comprehensive studies of diet and cancer in the world.  Adventist Health Studies are long-term health studies exploring the links between lifestyle, diet and disease among members of the seventh-day Adventist church, a Christian denomination that encourages a vegetarian diet and calls for abstinence from alcohol and tobacco. Adventists are ideal for epidemiological studies in that their similarity in lifestyle behaviours (such as not smoking) reduces the likelihood of confounding that is often present in other study groups.

A study titled ‘Vegetarian diets in the Adventist Health Study 2: a review of initial published findings’ was published in the American Journal of Clinical Nutrition in Jul 2014. Vegetarian dietary patterns in AHS-2 were associated with lower BMI values, lower prevalence of hypertension, lower prevalence of the metabolic syndrome, lower prevalence and incidence of diabetes mellitus, and lower all-cause mortality, and in some instances lower risk of cancer.

Another study titled ‘Patterns of plant and animal protein intake are strongly associated with cardiovascular mortality: the Adventist Health Study-2 cohort’ published in the International Journal of Epidemiology in Oct 2018, evaluated the association between specific patterns of protein intake with cardiovascular mortality in 81,337 men and women from the AHS-2. Strong associations were found between CVD outcomes and the animal protein factor that weighed heavily on meat products, whereas a specific plant protein factor weighing on nuts and seeds was associated with a lower risk of CVD mortality. Of the 2276 cardiovascular deaths during a mean follow-up time of 9.4 years, the ‘Meat’ protein factor increased the risk of deaths due to CVD by 61% whereas the ‘Nuts and Seeds’ protein factor reduced the risk by 40%. This strengthens the idea that protein sources may be key components of diet quality, possibly largely independent of other confounders, including vegetarian diet categories. Accordingly, the study concluded that associations between the ‘Meat’ and ‘Nuts & Seeds’ protein factors and cardiovascular outcomes were strong and could not be ascribed to other associated nutrients considered to be important for cardiovascular health.

Another important study ‘The Oxford Vegetarian Study: an overview’ published in the American Journal of Clinical Nutrition in Sep 1999, is a prospective study of 6000 vegetarians and 5000 non-vegetarian control subjects recruited in the United Kingdom between 1980 and 1984. The study found that the death rates from all causes, including ischaemic heart disease and all malignant neoplasms, were lower in vegetarians compared to meat-eaters.

Furthermore, a large number of studies have specifically examined the association of various nutrients/foods to some of the major lifestyle-related chronic diseases like cardiovascular diseases, type 2 diabetes and cancers. A discussion on these is beyond the scope of this post, however, in brief, the findings of these studies are in line with the findings of the above studies. These studies have also concluded that animal-based foods such as processed meats, unprocessed red meats, added sugars including sugar-sweetened beverages and refined grains increase the risk of various lifestyle-related chronic diseases while plant-based foods like fruits, vegetables, whole grains, legumes, nuts and seeds and n-3 fatty acids provide significant protection against these diseases.

More importantly, various studies have demonstrated that besides primary prevention, people with existing coronary heart disease and type 2 diabetes can derive significant benefits, even reversal, from making dietary changes, in conjunction with other lifestyle interventions such as exercise and stress reduction. Again, a detailed discussion on these is beyond the scope of this post.

Healthful eating: Sustainability of a dietary pattern

Besides the impact of diet on human health, there are growing concerns regarding the impact of food production on the environment. A large body of work has emerged on the environmental impacts of various diets, with most studies concluding that a diet rich in plant-based foods and with fewer animal source foods confers both improved health and environmental benefits. A growing body of evidence has emerged in the past decade showing that shifting diet from unhealthy animal-based foods (e.g., red meat and processed meat) to healthy plant-based foods (e.g., fruits, vegetables, and whole grains) might be associated with lower emission of greenhouse gases and thus might be more environmentally sustainable.

According to the WHO Technical Report Series 916, Diet, Nutrition and the Prevention of Chronic Diseases, it has been estimated that the number of people fed in a year per hectare ranges from 22 for potatoes and 19 for rice to 1 and 2, respectively for beef and lamb. The low energy conversion ratio from feed to meat is another concern since some of the cereal grain produced is diverted to livestock production. Likewise, land and water requirements for meat production are likely to become a major concern, as the increasing demand for animal products results in more intensive livestock production systems.

A recent ground-breaking initiative, ‘The EAT-Lancet Commission on Food, Planet, Health’ in 2019 offers valuable information on what is a healthy eating pattern for both human health and the health of the planet. The Commission observed that a large body of work has emerged on the environmental impacts of various diets, with most studies concluding that a diet rich in plant-based foods and with fewer animal source foods confers both improved health and environmental benefits.

The Commission recommends that healthy diets should have an optimal caloric intake and consist largely of a diversity of plant-based foods, low amounts of animal source foods, contain unsaturated rather than saturated fats, and limited amounts of refined grains, highly processed foods and added sugars. The Commission analysed the potential impacts of dietary change on diet-related disease mortality using three approaches (Comparative Risk, Global Burden of Disease and Empirical Disease Risk). All three approaches concluded that dietary changes from the current diets toward healthy diets are likely to result in major health benefits. This includes preventing approximately 11 million deaths per year, which represents between 19% to 24% of total deaths among adults.

As regards the impact of current dietary patterns on planetary health, the Commission observed that “Global food production threatens climate stability and ecosystem resilience. It constitutes the single largest driver of environmental degradation and transgression of planetary boundaries. Taken together the outcome is dire. A radical transformation of the global food system is urgently needed. Without action, the world risks failing to meet UN Sustainable Development Goals and the Paris Agreement.” It suggested – “Transformation to healthy diets by 2050 will require substantial dietary shifts. Global consumption of fruits, vegetables, nuts and legumes will have to double, and consumption of foods such as red meat and sugar will have to be reduced by more than 50%. A diet rich in plant-based foods and with fewer animal source foods confers both improved health and environmental benefits.”

A review article titled ‘Health and sustainability outcomes of vegetarian dietary patterns: a revisit of the EPIC-Oxford and the Adventist Health Study-2 cohorts’ published in the European Journal of Clinical Nutrition in Apr 2019 revisited two longitudinal studies comprising large proportions of vegetarians – the Adventist Health Study-2 (AHS-2) and the European Prospective Investigation into Cancer and Nutrition-Oxford (EPIC-Oxford) – to describe the food and nutrient intake, health effects, and environmental sustainability outcomes of the dietary patterns identified in these studies. The study found that greenhouse gas emissions of equicaloric diets are 29% less in vegetarian diets in AHS-2 and 47-60% less for vegetarian/vegan diets in the EPIC-Oxford than non-vegetarian/meat-eating diets. The study suggested that the beneficial health outcomes and reduced carbon footprints make the case for the adoption of vegetarian diets to address global food supply and environmental sustainability.

Food as Medicine: Diet prescription for prevention of lifestyle-related diseases

It is evident from the above data that modern food patterns have alarming implications for human health. In the light of the above evidence, it would be prudent to say that food has become undeniably important within the preventive medicine. The EAT-Lancet Commission Report, referred to above, argues that it is in fact ‘the single strongest lever to optimize human health and environmental sustainability on earth.’ In contrast to pharmacotherapy alone, a balanced whole-foods, mostly plant-based diet wields the power to not only prevent and treat but also reverse, myriad chronic illnesses including diabetes and blood pressure. Even simple changes, such as reducing saturated fat, cholesterol and salt intake and increasing dietary fibre, can have a huge impact on overall health and wellbeing, as well as the prevention of lifestyle-related chronic diseases.

Following the increased awareness of the importance of lifestyle for disease prevention, we are now seeing a resurgence of nutrition, or lifestyle in general, for disease management as well. Before coming to a discussion on what constitutes a healthy diet or healthful eating, it will be prudent to first briefly discuss some general guidelines/considerations.

Firstly, it is important to understand here that ‘we eat foods, not nutrients.’ So while it is important to have a working knowledge of the individual macronutrients and micronutrients, in real-life practice emphasis should be placed on whole foods and overall dietary patterns rather than individual nutrient recommendations. Besides, practical dietary advice based on the health effects of specific foods or food groups is much easier for the public to understand and implement than the recommended numerical criteria for various nutrients (e.g., 30% of energy from total fat).

Secondly, though from the above discussion it strongly emerges that a plant-based dietary pattern is not only good for human health, but for environmental sustainability as well, it needs to be understood that not all plant-based diets are created equal. For example, French fries or refined grains are plant-based foods but are considered unhealthy foods. As Hippocrates once said, ‘in food excellent medicine can be found, in food bad medicine can be found; good and bad are relative. Like all aspects of clinical practice, if utilised poorly, food can be equally as damaging as it can be remedial. For maximum benefit, dietary guidelines and lifestyle interventions should recommend increasing intake of healthy plant foods, while reducing intake of less healthy plant foods and certain animal foods for improved cardiometabolic health.

 In the case of all three macronutrients, the quality matters. Certain important aspects that need to be considered while choosing the three macronutrients for healthful eating, will be highlighted here in brief.

Carbohydrates

• Emphasize high-quality, low GI carbohydrate sources. Essentially high-quality carbohydrates are found in foods that are in their whole or minimally processed forms. In contrast, low-quality carbohydrates come in the form of refined grains and highly processed foods and juices and added sugars. Broadly, the high-quality carbohydrates include:
  • Whole grains
  • Fruits and vegetables
  • Legumes (lentils and beans)
  • Nuts and seeds

            These foods are high in fibre, vitamins, minerals and phytonutrients, which help to   

            make them high quality.

• Increase fibre intake.
• Limit processed foods and added sugar, which besides being bereft of various nutrients, have a high GI.

Proteins

The type of protein we eat is very important. Plant-based proteins come packaged with countless other important nutrients such as vitamins, minerals, phytonutrients, and fibre. In contrast, animal-based proteins are often high in saturated fat and cholesterol and as discussed, these have been linked to various chronic diseases, including heart diseases and type 2 diabetes. As a result, plant-based proteins are the optimal choice over animal-based proteins. Replacing animal-based proteins with plant-based proteins is the key to get healthy proteins.

Fats

Fat is a complicated nutrient. When it comes to fats, the bottom line is two folds:

• First, just like carbohydrates and proteins, the type matters. Emphasize unsaturated fats and reduce saturated fats and trans fats.
• Second, as for proteins, replacement is the key. Replace unhealthy saturated and trans fat sources with healthy unsaturated fats found mostly in plant foods and oily fish.

Finally, ‘diet choice’ is a complex area and mere scientific recommendations for a particular dietary pattern are not sufficient to bring about a change in the dietary pattern of individuals/populations. Unfortunately, despite overwhelming evidence that healthful eating patterns can significantly improve health, large sections of the population globally continue to engage in unhealthy eating patterns. In this context, it would be pertinent to understand the factors that govern ‘diet choice.’ Besides, diet choice not only influences the health and wellbeing of individuals, families, and communities, but also influences the agriculture, environment, business, culture, and economy at local, regional, national, and global levels.

The key determinants of diet choice include:

1. Biological determinants such as hunger, appetite, and taste.
2. Economic determinants such as cost and income.
3. Physical determinants such as access, education, skills and time.
4. Social determinants such as social class, culture and social context.
5. Psychological determinants such as mood, stress and guilt.
6. Attitudes, beliefs and knowledge about food, and optimistic bias.

However, a detailed discussion on these is beyond the scope of this post.

Though, as discussed above, there is enough evidence to link various nutrients/foods to health and disease, however, as discussed ‘diet choice’ is a complex area and many factors affect the population’s and an individual’s choice of food. In this background, it is neither prudent nor practicable to prescribe an exact diet for the entire global population. Instead, empirical food groups, which combined in a diet, would optimize human health, would be outlined here. Local interpretation and adaptation of these universally-applicable dietary guidelines can be done based on the culture, geography and demography of the population and individuals. For ease of understanding, healthy eating plans depicted as ‘healthy eating plates’ from prominent medical organisations as well as some global nutrition recommendations will be discussed here.

Healthful eating: Dietary recommendations of prominent medical organisations.

Now let us look at the dietary recommendations of some prominent medical organizations for the prevention of lifestyle-related chronic diseases. The 2019 ACC/AHA Guideline on the Primary Prevention of Cardiovascular Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines’ was published in the journal of the American College of Cardiology in Sep 2019. Of the various recommendations, the guidelines stated that the most important way to prevent atherosclerotic vascular disease, heart failure and atrial fibrillation is to promote a healthy lifestyle throughout life. As regards the diet the guidelines recommended that ‘all adults should consume a healthy diet that emphasizes the intake of vegetables, fruits, nuts, whole grains, lean vegetable or animal protein, and fish and minimises the intake of trans fats, red meat and processed red meats, refined carbohydrates, and sweetened beverages.’ Importantly, the dietary guidelines of the American Cancer Society and the American Diabetes Association for the prevention of cancers and diabetes, respectively, as well as for general health promotion, are consistent with the above guidelines.

Healthful eating: Global Nutrition Recommendations

Here we will briefly discuss some prominent global nutrition recommendations for healthful eating.

MyPlate from Dietary Guidelines for Americans (DGA) 2020-2025

The DGA lays down the following broad guidelines to promote health and prevent disease.

1. Follow a healthy dietary pattern at every life stage. At every life stage-infancy, toddlerhood, childhood, adolescence, adulthood, pregnancy, lactation, and older adulthood-it is never too early or too late to eat healthfully.
2. Customize and enjoy nutrient-dense food and beverage choices to reflect personal preferences, cultural traditions, and budgetary considerations.
3. Focus on meeting food group needs with nutrient-dense foods and beverages, and stay within calorie limits.

An underlying premise of the Dietary Guidelines is that nutritional needs should be met primarily from foods and beverages-specifically, nutrient-dense foods and beverages. Nutrient-dense foods provide vitamins, minerals, and other health-promoting components and have no or little added sugars, saturated fat, and sodium. A healthy dietary pattern consists of nutrient-dense forms of foods and beverages across all food groups, in recommended amounts, and within calorie limits.

The core elements that make up a healthy dietary pattern include:

• Vegetables of all types– dark green; red and orange; beans, peas, and lentils; starchy; and other vegetables.
• Fruits, especially whole fruit.
• Grains, at least half of which are whole grain.
• Dairy, including fat-free or low-fat milk, yogurt and cheese, and/or lactose-free versions and fortified soy beverages and yogurt as alternatives.
• Protein foods, including lean meats, poultry and eggs; seafood; beans, peas, and lentils; and nuts, seeds, and soy products.
• Oils, including vegetable oils and oils in food, such as seafood and nuts.
• Limit foods and beverages higher in added sugars, saturated fat, and sodium, and limit alcoholic beverages. Limits are:
  • Added sugar-Less than 10 percent of calories per day starting at age 2. Avoid foods and beverages with added sugars for those younger than age 2.
  • Saturated fat-Less than 10 percent of calories per day starting at age 2.
  • Sodium-Less than 2,300 milligrams per day-and even less for children younger than age 14
  • Alcoholic beverages-Adults of legal drinking age can choose not to drink, or to drink in moderation by limiting and take to 2 drinks or less in a day for men and 1 drink or less in a day for women, when alcohol is consumed. Drinking less is better for health than drinking more. There are some adults who should not drink alcohol, such as women who are pregnant.

Canada’s Dietary Guidelines

Health Canada, the federal department responsible for the health of people of Canada, in 2019 published Canada’s Dietary Guidelines to promote healthful eating and overall nutritional well-being. It laid down the following guidelines for intake of foods that make up patterns of eating associated with positive health outcomes.

Guideline 1

Nutritious foods are the foundation for healthful eating.

• Vegetables, fruit, whole grains, and protein foods should be consumed regularly. Among protein foods, consume plant-based more often.
  • Protein foods include legumes, nuts, seeds, tofu, fortified soy beverage, fish, shellfish, eggs, poultry, lean red meat including wild game, lower-fat milk, lower-fat yogurts, lower fat kefir, and cheeses lower in fat and sodium
• Foods that contain mostly unsaturated fat should replace foods that contain mostly saturated fat.
• Water should be the beverage of choice.

Guideline 2

            Processed or prepared foods and beverages that contribute to excess sodium, free sugars, or saturated fat undermine healthy eating and should not be consumed regularly.

Guideline 3

            Food skills are needed to navigate the complex food environment and support healthy eating.

• Cooking and food preparation using nutritious foods should be promoted as a practical way to support healthy eating.
• Food labels should be promoted as a tool to help Canadians make informed food choices.

Besides health as its primary focus, Canada’s Dietary Guidelines also highlight the potential environmental benefits of the above recommended dietary patterns. There is evidence supporting a lesser environmental impact of patterns of eating higher in plant-based foods and lower in animal-based foods. The potential benefits include helping to conserve soil, water and air.

EAT-Lancet Commission Guidelines

The EAT-Lancet Commission on Food, Planet, Health, referred to above, offers valuable information on what is a healthy eating pattern for both human health and the health of the planet. According to the report, a diet rich in plant-based foods and with fewer animal source foods confers both improved health and environmental benefits. Overall the literature indicates that such diets are “win-win” in that they are good for both people and the planet.

Healthy diets have an optimal caloric intake and consist largely of a diversity of plant-based foods, low amounts of animal source foods, contain unsaturated rather than saturated fats, and limited amounts of refined grains, highly processed foods and added sugars. The ‘planetary health plate’ depicted in the report consists by volume of approximately half a plate of vegetables and fruits; the other half, displayed by contribution to calories should consist of primarily whole grains, plant protein sources, unsaturated plant oils, and (optionally) modest amounts of animal sources protein.

In brief, this is a flexitarian diet, which is largely plant-based but can optionally include modest amounts of fish, meat and dairy foods. It emphasizes fish, vegetables, fruit, legumes, whole grains, and nuts and recommends limiting the intake of red meat and starchy vegetables; eggs, poultry and dairy foods are categorised as optional.

Another prominent Health Organization the American College of Lifestyle Medicine, based on available evidence has recommended that – “for the treatment, reversal and prevention of lifestyle-related chronic diseases, an eating plan based predominantly on a variety of minimally processed vegetables, fruits, whole grains, legumes, nuts and seeds is recommended.”

Plant-based diet

It would be prudent to clarify here that though a ‘plant-based diet is essentially a diet that emphasizes the healthful plant-based foods in their whole or less-processed form, it does not necessarily have to be 100% plant-based.

All the above nutrition recommendations follow broadly a similar pattern, focusing on predominantly whole, plant-based foods, with greater emphasis on fruits and vegetables, and minimal amount from animal source foods. In the light of the scientific evidence, plant-based foods are the ideal choice for both human health as well as environmental sustainability. However, as is evident from the various factors that determine ‘diet choice’, mere scientific recommendations are not enough to bring out changes in the diet patterns of individuals, as the food choice is strongly influenced by sociocultural and economic factors. In this background, EAT-Lancet Commission’s ‘planetary health plate’ appears to be the most balanced approach.

Food as Medicine: Fruits and vegetables

As seen in all the above nutrition recommendations, fruits and vegetables occupy an important place in the recommended diet plans of all of the above organisations/institutions. In the context of fruits and vegetables, consume a ‘rainbow’ of fruits and vegetables. This ‘eat by colour’ approach encourages people to eat a variety of colourful plant foods. These foods contain a plethora of not only vitamins and minerals, but perhaps, most importantly, phytonutrients. These phytonutrients have known pleiotropic effects on cellular structure and function, ultimately resulting in the modulation of protein kinases and subsequent epigenetic modification in a manner that leads to improved outcomes. Ensuring the consumption of a variety of foods will enable the individual to sample from thousands of phytochemicals that may help to offset an increased risk of chronic disease.

Food as Medicine: Animal versus plant proteins      

In individuals/populations with patterns of eating that include animal-based foods, emphasize more plant-based foods, and promote animal-based foods that are lower in saturated fat, such as lean red meat including wild game, lower-fat milk and milk products, and cheeses lower in fat and sodium.

Guidelines for transitioning from an unhealthy eating pattern to a healthful eating

The complexity of food choice is obvious from the above discussion, which is in itself not exhaustive. Besides, the factors affecting food choice will vary according to life stage and the power of one factor will vary from one individual or population group to the next. Thus ‘one size fits all’ strategy to modify food choice behaviour will not be suitable for all population groups. Rather interventions need to be individual/population-specific with consideration to the multiple factors influencing their decision on food choice.

Applying the concept of the dietary spectrum for healthful eating

The dietary practices at the population level can be considered to lie on a spectrum. At one end of the spectrum is an unhealthy dietary pattern, rich in animal-based foods and refined and processed foods and at the other end of the spectrum, we have the most prudent healthy diets meant to address various lifestyle-related chronic diseases and promote good general health. Individual dietary patterns will lie somewhere along this spectrum. So, before making any changes to one’s dietary pattern, the following aspects need to be considered:

• Individual’s current health status and health goals based on the health status.
• Where does one’s current dietary pattern lie on the spectrum?
• Individual’s readiness and confidence to make changes.

A ‘diet action plan’ will be individualised taking into consideration the above factors. The presence and severity of a disease and risk factors will determine the appropriate placement along the dietary spectrum. A patient aiming to treat or reverse a chronic disease will likely see more improvements, the more they shift towards the right end of the spectrum.

Healthful eating: Make changes gradually and focus on small steps

Changing lifelong nutrition behaviours can seem overwhelming, however, even exceedingly small shifts can have an effect. An editorial title ‘United Nation’s dietary policies to prevent cardiovascular disease’ published in the journal BMJ in Sep 2011, highlighted eight dietary targets to be prioritised for the prevention of cardiovascular disease. Six are aimed at increasing the consumption of healthy foods and two at limiting specific harmful nutrients. The proposed targeted changes are modest, reflect changes achieved in population-based interventions, and are supported by observed consumption distributions within and across countries. Meeting any one target would produce substantial benefits.

Target changes and benefits	Reduction in relative risk of cardiovascular mortality (%)	Estimated fewer global cardiovascular deaths (range) in millions
Reasonable target change
Increase fruits by 1 serving/day	~8	1.6 (0.8-2.0)
Increase vegetables by 1 serving/day	~7	1.4 (0.7-1.8)
Increase whole grains by 1 serving/day	~10	2.0 (1.0-2.5)
Increase nuts by 2 servings/week	~11	2.2 (1.1-2.8)
Increase vegetable oils by 1.5 servings/day	~5	1.0 (0.5-1.3)
Increase seafood omega-3 fatty acids by 50 mg/day	~5	1.0 (0.5-1.3)
Reduce sodium by 0.8 g/day	~6	1.2 (0.6-1.5)
Reduce industrial trans fats by 1% energy	~7	1.4 (0.7 to 1.8)
Benefits
Total benefits per year (multiplicative risk reduction)	~52	10.4 (5.2-13)
Total benefits over 3 years		30 (15.6-39)

The eight targets together could halve global cardiovascular disease, annually preventing more than five million premature deaths from cardiovascular disease (and 10 million deaths from cardiovascular disease overall), while simultaneously reducing obesity, diabetes and common cancers. Over just a few years, these modest dietary improvements could prevent one million deaths from cardiovascular disease in the US and 30 million worldwide.

Another more recent study, titled ‘Association of Changes in Diet Quality with Total and Cause-Specific Mortality’ published in the New England Journal of Medicine in Jul 2017, evaluated the relationship between changes in diet quality over time and the risk of death. The authors assessed total and cause-specific mortality among 47,994 women in the Nurses’ Health Study and 25,745 men in the Health Professionals Follow-up Study from 1998 through 2010. Changes in diet quality over the preceding 12 years (1986-1998) were assessed with the use of the Alternate Healthy Eating Index-2010 score, the Alternate Mediterranean Diet score, and the Dietary Approaches to Stop Hypertension (DASH) diet score. The study found that a 20-percentile increase in diet scores (indicating improved quality of diet) was significantly associated with a reduction in total mortality of 8 to 17% with the use of the three diet indexes and a 7 to 15% reduction in the risk of death from cardiovascular disease with the use of the Alternate Healthy Eating Index and Alternate Mediterranean Diet, compared to the risk among participants with consistently low diet scores overtime.

Therefore, it needs to be emphasised that every food choice is an opportunity to accumulate benefits, and even small ones add up. Furthermore, it is easier to make and sustain gradual changes to your eating habits rather than trying to revamp them overnight. Modest changes made over a period of time add up into a lifelong healthy eating habit.

Healthful eating: Focus on positive adding vs restricting

Begin by adding healthier food options to your diet instead of cutting down foods that are considered less healthy/unhealthy. This enables people to start their journey on a positive note and often leads them to naturally start crowding out the less healthy food that they might be eating.

Healthful eating: Make simple swaps

For more healthful eating, start with simple changes like swapping whole milk for fat-free or skimmed milk. One cup of whole milk contains 149 kcal, whereas the same quantity of fat-free milk contains only 86 kcal. Besides, it significantly reduces the intake of saturated fatty acids and cholesterol. Over time, you can swap even soy milk to skimmed milk. Such changes are almost unnoticeable but can provide significant health benefits.

A study titled ‘Dietary Protein Intake and Risk of Type 2 Diabetes in US Men and Women’ published in the American Journal of Epidemiology in Apr 2016, investigated the associations between intake of protein and protein type and the risk of type 2 diabetes. The study found that substituting 5% of energy intake from vegetable protein for animal protein was associated with a 23% reduced risk of type 2 diabetes.

Identify support networks

Identify your support network from within the family and friends. People are much more likely to be successful when they have a support system to lean on.

I have discussed healthful eating practices, specifically in the context of obesity, in my post Diet Plan for Weight Loss – It’s going to be a journey. To dispel some popular myths related to weight loss, I have also discussed some of the popular dietary practices in the context of weight loss – Very Low-Calorie Diet – All You Need to Know; Keto Diet – Debunking the Myth, and Say NO to Fad Diets.

Healthful Eating – A Lifelong Journey

While planning dietary changes, the dietary spectrum can be compared to a long journey-lifelong-that an individual is embarking on. The pace and the distance travelled on this metaphorical journey will be determined by the readiness of the individual to implement change, ability (knowledge and skills) to make these changes and the ‘belief’ in their ability to make these changes. Importantly, while their final destination may be close to that ‘North Star’ (a metaphor for the evidence-based ideal eating pattern for that individual’s health status), the nutrition action plan will likely need to be met out, as highlighted, one small step at a time; each meal serves as an opportunity to move closer to their goal.

As in other spheres of life, challenges in the form of social situations, travel, busy weeknights – when you can’t adhere to a healthy eating pattern, can be expected here on this ‘journey’ too. But remember that it’s the overall dietary pattern over a period of time that shapes health, not perfectly selecting every individual food or meal every single day. Furthermore, this journey along the dietary spectrum will be more rewarding and sustainable, if the goals are set in accordance with the readiness, ability and confidence of the individual to make these changes. That ‘North Star’ dietary prescription may not be achievable for every person, but as highlighted, even small steps in that direction are meaningful and important and can provide significant health benefits. So, rather than pursuing perfection, focus on the progress that will help you build sustainable habits through small incremental steps.

Finally, look at food as part of the wider panorama of lifestyle medicine, and do not disregard the other equally, if not more, important pillars of lifestyle medicine, such as exercise. The obscured view of food as medicine, which unabashedly over-emphasizes the health properties of certain food types and disregard for the other important aspects of lifestyle medicine, has perpetuated the damaging ‘diet’ culture globally. Hippocrates had declared that ‘eating alone will not keep a man well’ reiterating that while a balanced diet irrefutably forms the scaffolding of good health, it is not the only player in a comprehensive lifestyle approach to good health. I have discussed the health benefits of exercise, another important pillar of lifestyle medicine, in great detail in my post, Health Benefits of Exercise: a grossly underutilised therapy. I have even discussed the exercise prescription guidelines for optimum health benefits in my posts – Exercise Prescription for Optimum Health benefits; Aerobic Exercise Prescription for Optimum Health benefits; and Weight Training Program design for Optimum Health.