On Human Nutrition: Frequency of Meals, and How Much to Eat?

I read with interest an article on nutrition written by Datuk Dr Nor Ashikin Mokhtar, a consultant obstetrician and gynecologist, and a functional medicine practitioner. She wrote in The Star today (10 December 2023) on “How many meals to eat.”

Nutrition probably is the most interesting, the most popular and widely read subject among all health and medical subjects. It is widely read by most people, including doctors, nutritionists, food scientists and just ordinary laymen alike.

 It is probably the only subject that appeals to most people because food and nutrition is the only ingredient that gives us health and life, and yet nutrition is the most complex subject to understand. Several US $ billion are being spent yearly on research on nutrition, resulting in thousands of research papers being churned out every year, and yet we understand just a bit how food affects our body, and overall health.

Nutrition is so complex to fully understand that resulted in many research findings contradicting each other.  Our understanding on nutrition today is far more than just our knowledge about the proximate principles, namely, carbohydrates, protein, and fat how they are metabolized through the Hans Krebs Cycle and other metabolic pathways to yield energy and body needs, besides the wide spectrum varied roles of various vitamins, and minerals and trace elements. Besides these nutrients, nutritional and food scientists have over the years discovered untold tens of thousands of other functional compounds especially the phytochemicals in plant-based foods besides the traditional carbohydrates, proteins, fats, vitamins and minerals.

Nutrition and food scientists are now trying to unravel the medicinal properties of these functional foods containing tens of thousands if not tens of millions of these phytochemicals and their roles in health, in the prevention of disease and their curative values when consumed in small amounts over long periods of time.

 Truly, Hippocrates, Father of Medicine once said: “Let Food be Thy Medicine” He never said “let medicine be thy food” which the pharmaceutical companies and doctors today put words into his mouth long, long after his death for obvious monetary reasons.

On the very interesting and challenging question “how many meals to take” Datuk Dr Nor Ashikin Mokhtar was trying to discuss, I don’t think anyone really knows. She has discussed several interesting issues to determine the frequency between meals, among them are enhanced satiety, metabolic kickback, steadier energy levels, blood sugar control, meal frequency and chronic disease, meal frequency and weight loss, metabolic boost from frequent meals, meal frequency and athletic performance, diet quality, and which to choose.

 She also mentioned some might find it more beneficial to eat small, but frequent meals, while others prefer the usual three -meals-a-day structure. She has discussed these issues very interestingly that I enjoyed reading.

From my angle of perspective, we do not know how much nutrients – energy from carbohydrates, proteins and fats are recommended as our Recommended Daily Allowances (RDA) as these recommendations are not fixed as they keep changing every 5 years by expert committees on nutrition.  Each country has its own “Recommended Daily Allowances” depending on the Chairman sitting in these committees, and their recommendations keep changing for review every few years. I have studied the RDA and found they are a bit inflated over our actual basic needs especially in energy (caloric) from carbohydrate, and fats.

Nutritionists have yet to determine what constitutes “optimal nutrition” for an individual as this would vary from person-to-person due to individual biological variations based on our needs, occupation, age, gender, physical activities, body build, possibly climate and environment too. We have yet to define optimal health which would depend on the nutritive quality of the food, optimal time and frequency of eating to provide optimal nutrition for different individuals. Without understanding these criteria for optimal health, we would not be able to determine how much to eat, what to eat and how often we need to eat?

 It only shows how little we understand nutrition despite the avalanche of research papers churned out yearly with the highest research budgets and research fundings given out for nutrition, with research on cancer coming only next.  

My feeling on how many meals to take and their frequency a day would depend on our individual body needs and how our body signals to us through hunger. We can’t dictate what and when the body should have them. The body has an inborn and innate feedback mechanism to signal us and to decide for us when we should eat. If we decide and dictate to our body, for instance the traditional way of having 3 meals – breakfast, lunch, dinner, and even supper for some individuals, I think we would be overeating.

Nutritionists consider overeating as bad nutrition or malnutrition as much as under eating is also malnutrition since the Latin word “mal” means “bad”. Hence “malnutrition” applies to both overnutrition as well as undernutrition which may surprise many of my readers.

We know that overeating results in obesity, type 1 diabetes, cardiovascular disease, renal disorders, stroke, metabolic syndrome, gout, and other nutritional lifestyle diseases, and probably cancers too. Bear in mind there are many poor communities throughout the world, especially in countries where families do not have one meal a day, and yet they live relatively healthily though optimal health is extremely difficult to define.

My feeling on this issue is to allow the body to signal us when blood sugars are low, but not too low causing hypoglycaemic attacks. Hunger and the desire for food sets in automatically, and we eat only in moderate amounts to bring up blood sugar levels to slightly above pre-prandial levels.

Bear in mind the body cannot utilize excessive sugars than it needs when large meals are taken. It will be stored as glycogen, and if not used up, turned into fats. Neither can the body store excess proteins when too much meat is consumed in one meal. It too will turn into fat and not into muscles.

In other words, the long-term effects of overeating and overnutrition causes some of the calories to build up as fat causing overweight. Overweight leads to obesity, and if this is not controlled it slips into pathological obesity. This increases risk for cardiovascular diseases, type 1 diabetes, metabolic syndrome, possible cancer and other chronic health problems.

Excessive eating may also overload the digestive system.  The limited secretion of digestive enzymes is also being overstretched, resulting in indigestion.

It may also influence the sleep rhythm. The circadian clock, which controls the wake-sleep-wake cycles, causes the sleep and hunger hormone levels to rise and fall throughout the day. Overeating may impact this rhythm resulting in difficulty in sleeping.

 

My opinion is, take only two moderate meals a day, spaced out over an 8-to-10-hour interval. This will also give bowel rest as well as metabolic rest to the liver that need to store, break down the nutrients or detoxify products of metabolism such as protein into ammonia into urea and creatinine as well as to prevent the continuous production of free radicals produced by the continuous metabolic breakdown of food, let alone the kidneys that need to excrete urea, creatinine and other metabolic wastes. In short, I think we need to ensure that our body is allowed bowel, liver, kidneys and all metabolic rest between meals.

Furthermore, excessive protein intake a day can also result in elevated blood lipids and cardiovascular events because many high-protein foods also contain saturated fat, although sugar (sucrose) would be the main culprit leading to coronary heart disease as shown by Professor John Yudkin, a very eminent physician, physiologist, chemist who was also the Chair of Nutrition at the University of London in the mid 1960’s. Yudkin showed that pure white sugar is more deadly  than saturated fats in causing coronary heart disease. Yudkin’s findings caused a stir at that time over the saturated fat theory but currently his sugar findings are revived and accepted by many nutritionists and scientists world-wide.  It is just our advances in our understanding in nutrition and medicine with new findings.

  Excessive protein intake too causes an overload to the kidneys, adding to the risk to those predisposed to kidney disease.

I should think taking just two moderate meals a day allows bowel, liver, metabolic and kidney rest in between the 24 hours.  That would scientifically, and logically be the best approach rather than the traditional regimen of having three-square meals a day whether the body requires them, only to be stored as body fats leaning to obesity and nutritional lifestyles pathological events.

I should advise not just two moderate balanced meals a day with high fruits and vegetable contents that have the benefits of medicinal phytochemicals and antioxidants in them, but more importantly caloric restriction that can prolong longevity, not just longer life span, but also disease-free longevity.

As far back as in 1935, Clive McCay and his colleagues at Cornell University clearly demonstrated when rats were given severely restricted diets, they lived up to 33% longer than their normal lifespan. Over the last few decades, similar experiments carried out on countless species, from worms to rodents and even primates have shown the same results, probably due to reduced toxic metabolic wastes. The excessive calories that need to be metabolized resulting in excessive free radicals generated besides toxic metabolic wastes produced.

I think this subject on how frequent and how much to eat is a very complex question which all clinicians, biological and medical scientists and even qualified nutritionists need to understand as there is no one answer that fits all individuals.