Updated: Dec 6, 2018
It is clear that strict adherence to any FAD/starvation diet can induce rapid weight loss. However, maintaining weight loss appears to be significant more challenging. In this article, I will highlight some of main problems with modern weight-loss strategies, and educate the reader on how I approach these common issues in my practice.
Poor quality dietary advice of the 20th & 21st century
The rates of obesity in the UK are currently at an all time high, and are much worse than the rest of our European counterparts. In fact, if the current trend carries on as it has done, one in two Britons will be obese by 2045.
Although the reasons for this are probably numerous, a shift in mainstream dietary advice regarding saturated fats appears to have played a role.
Based on some questionable research findings presented by Ancel Keys in the 1950's, public health recommendations were implemented to replace saturated fats with "heart healthy" vegetable oils in hopes of reducing cardiovascular disease and obesity.
As can be seen in the three graphs below, beginning around 1974, Britons started consuming less saturated fat in the form of red meat, whole milk, and butter. Instead, they began to replace these nutrient-rich and healthy fats with chemically processed vegetable oils, vegetable spreads, and skimmed milk.
It would be logical to assume that if saturated fats caused obesity, then reducing consumption would also reduce obesity rates. But no, the graph below shows that obesity rates have been steadily increasing since at least 1980.
Interestingly, there is actually a negative correlation between saturated fat intake and obesity, meaning that as the public consumes less they are statistically more likely to become obese.
Since correlation does not imply causation, it is difficult to draw any solid conclusions from these data. However, it should certainly provide people with some "food for thought".
For an exquisite review of the research on saturated fats, the health benefits of dietary cholesterol, and the potentially detrimental consequences of saturated fat restriction, I highly recommend reading the book The Big Fat Surprise .
Malnourishment is common in obesity
Through replacing whole foods with man-made, processed alternatives, humans effectively deplete themselves of essential nutrients required to process calories from foods. The process of refining foods depletes many of the micronutritients (vitamins, minerals, and phytochemicals), and the remaining "food" is then pumped full of artificial preservatives and other chemicals to increase aesthetics, taste, and shelf-life. These processed foods are known as "empty calories", and can quite easily humans lead to sub-clinical chronic malnourishment.
Obesity can be caused by an excess of macronutrients (carbohydrate, fat, and protein), and a deficit in micronutrients. This is because burning macronutrients for energy requires a continual supply of micronutrients. Excess consumption of empty calories can render a person obese and malnourished simultaneously.
This is why food quality probably matters just as much as food quantity. A diet based on nutrient-dense whole foods, devoid of excessive carbohydrate, refined vegetable oils, and artificial chemicals is clearly the most suitable option. In many cases, supplementation with extra vitamins or minerals may also be necessary for a period of time.
Different types of foods elicit different hormonal responses
Without going into too much detail, lets take a 500 kcalorie meal. In many situations, the body will respond differently to 500 calories of breakfast cereal than it will to a 500 calorie omelette.
First lets have an (oversimplified) look at the breakfast cereal : When refined carbohydrate is digested, it is rapidly absorbed into the blood. In response, the body releases the hormone insulin, which takes the sugar and helps it get into the cells to be burned for energy. For a healthy individual, this is a tight-knit system which works fairly well. However, for anyone who is overweight, this system is potentially impaired.
Instead, when sugar cannot be effectively burned for energy, it can be preferentially stored as fat tissue (via the action of insulin). In basic terms: foods which spike blood sugar and trigger large insulin release promote fat storage in many people. These foods include bread, cereals, sugars, juices, and other simple carbohydrates.
On the other hand, an omelette which is rich in protein, fat, and other nutrients is slow to digest. The slow release of fatty acids and amino acids does not elicit much of an insulin response, and instead provides a steady source of energy throughout the morning.
Furthermore, there are a whole host of other hormones and neurochemicals involved in response to different food types and combinations. Each is involved in governing whether someone feels "hungry" or "full", and control the rate at which the body burns energy. In short, two people can eat the same diet, yet one person may lose more weight than the other person due to individual biochemical factors governing energy expenditure.
In addition, aside from the amount of food eaten and the amount of exercise performed, the amount of sleep people get is also a crucial player in achieving weight loss. Disordered circadian rhythms can independently cause obesity through disrupting whole hormonal milieu. This is why it is so important to focus on improving sleep in conjunction with any other strategy employed.
Meal Timing is just as important as meal composition
Just as the body responds to different types of foods in different ways, the TIME that food is eaten also plays a major role in what the body actually does with that energy. Ever heard of the good old saying:
"Breakfast like a king, lunch like a prince, dinner like a pauper" ?
Well the research is beginning to show that this approach is actually bang on the money. Calories consumed early in the day are more likely to be burned for energy. Alternatively, eating large meals late at night promotes fat storage, because the body do not need to use that energy when asleep in bed! The simple solution to this is to eat most calories in the morning and early on in the daytime.
People can't make up for a poor diet by going for a jog
Here is a shocker: cardio exercise does not do much to burn off excess fat. Anyone who says that people just need to "exercise more" to lose weight either doesn't understand human physiology, or is simply trying to sell a product. We have known this fact for a long time, but just for those interested - a recent meta-analysis found that "neither short-term high-intensity nor medium-intensity continuous training produced clinically meaningful reductions in body fat."
The amount of fat burned whilst sitting, walking, and jogging, is not that much different. Instead, the main determinant of how much fat the body burns (the resting metabolic rate) is lean muscle mass. This means that more muscle = higher metabolic rate = more fat burning at rest. People who are overweight or obese typically have less lean muscle mass, despite larger body mass, than their leaner counterparts.
If muscle-mass determines the metabolic rate, then building/maintaining muscle should theoretically improve fat loss. Interestingly enough, there is some research to support this notion.
An effective weight loss strategy is not simply based on calorie counting. It should be based on nutrient dense foods unrefined foods, and include food choices and eating habits which promote satiety. It should also take into consideration underlying biochemical and hormonal imbalances which may affect a persons ability to burn fat. It should be designed individually, taking into consideration each persons specific needs and requirements. Furthermore, it should be coupled with the right amount of strength training and sleep management.