Understanding why diets don’t work, and practical guide for sustainable weight loss
Theoretically, the first rule of metabolism takes the form of a thermodynamic equation:
(Energy IN) minus (Energy OUT) = Energy STORED.
Food contains energy, which the body converts into heat, movement and thought. These activities in turn burn off energy. If you eat more calories than you expend, you’ll store unused energy in fat cells.
So according to this equation, weight loss should be simple! All we have to do is burn more energy than we consume. This is the advice we’ve been receiving from many doctors, diet experts and almost all diet programs for years. But to what results??
In reality however, our body doesn’t function in such away. After initial success losing weight, many dieters experience the plateau of weight loss, and after some time gain more weight than before, and often move onto trying a different diet program, to be repeated again, and again.
To understand how to balance our weight, first we need to understand the physiology of starvation and negative feedback system which regulates our use of energy.
When we reduce calorie consumption, our body triggers our innate negative feedback. Faced with starvation, the body tries to save as much energy as possible by lowering metabolic rate. The body can’t tell if the calorie restriction is the result of famine or our own free will, so it takes the safety-first approach and activates the energy-conserving switch that maximises its chance of survival.
Our metabolism does not return to its previous level once this period of dieting (or famine) is over. We continue to burn fuel more slowly and store energy in our fat cells.
All this explains why diets don’t work!
Key message: Calorie restriction lowers metabolic rate and our biology rebels against starvation.
Our bodies are designed to control weight through hormonal messengers. Fat cells in our bodies release a hormone called leptin to communicate with our hypothalamus, the brain’s weight-control centre. Leptin conveys to brain how much energy the body has stored; brain uses this information to operate two switches: ON/OFF hunger; RAISE/LOWER metabolism.
When we overeat and store more energy in fat cells, fat cells release leptin into the blood stream; the hypothalamus reads this message, realises that the body has enough energy, and triggers both switches; hunger lowers and metabolism speeds up. This constrains energy intake and depletes existing energy stores more rapidly, thus preventing runaway weight gain.
But leptin also controls weight gain. When we restrict calories, lowering the amount of leptin in our blood, the hypothalamus takes this as a cue to increase appetite and reduce metabolism. Triggering these switches therefore slows weight loss and leads to rapid weight gain once food becomes freely available again!
Key message: Our bodies are designed to control weight through hormonal messengers.
All this suggests that our bodies are designed to keep us in good shape and prevent us from eating too much, gaining, or losing too much weight! But we all know, this isn’t the case – Obesity is a global health epidemic, especially in the western world.
Our ancestors were hunter-gatherers. Meat and starchy food made up the bulk of their diet. Natural vegetables, fruits, nuts, seeds and herbs rounded out their meals.
Key message: Our physiology and bodies still resemble those of early homo sapiens, but the energy we use to fuel them could not be more different.
Almost 60% of our daily calorie intake – in the western countries - comes from highly processed foods. We eat a lot less good natural fat and a lot more sugar and industrially processed vegetable oils than humans ever have in our species’ history.
This shift in energy-use from sugars and processed foods has sabotaged the negative feedback system that is designed to protect us against obesity.
Key message: The modern western food environment overrides the biological system and is a recipe for modern day obesity.
The level of energy (fat) storage that our brain calculates is necessary for our survival is called our “weight set-point”. It is like the thermostat that controls the temperature in our house – It will reach, and then maintain the level that it is set at, by using negative feedback system (as explained above).
Unfortunately, weight set-point is not always set at a healthy weight. If you consciously try and lose weight by traditional means, it then becomes a struggle of wills between your conscious desire to be a particular weight and your brain’s subconscious power to regain its desired weight set-point. Invariably – but unfortunately for all dieters – biology always wins.
Key message: Our environment and genetics determine our weight set-point; when we truly understand how our bodies regulate our weight set-point, only then can we beat obesity.
Few practical tips for regulating weight
1. Addressing leptin resistance – condition when our brain can’t sense the high levels of leptin in our blood - is critical for weight management. High levels of insulin results in more leptin resistance and more leptin resistance means a higher weight set-point.
a. Rely lesson sugars and processed food as primary energy source to reduce high levels of insulin; incorporate more sleep, breathing exercises, reduce stress levels, add more movement and other helpful habits that will help regulate insulin levels
2. Altering weight set-point: High calorie processed foods increase our weight set-point. So, it’s not the amount of food we eat that will alter the weight set-point, but it is the quality of the food.
a. Focus on increasing natural food in your daily diet, as high calories from natural foods such as good fats, will not affect weight set-point
