Why Low-Calorie Diets Do Not Work & Never Will Do - FBL

Why Low-Calorie Diets Do Not Work & Never Will Do


Simple, right? If you intake less calories than your body needs, the smaller we become. Technically, this is true, but at what cost and for how long does this work. If it did work, then surely everyone by now would be super thin and dieting would a piece of cake. However, it is not that simple and here is why.

Rather than excess calories being sole reason for weight gain, modern research has found that there is another culprit in the form of a hormone called leptin.

Leptin – The Master Hormone

When we think of our fat, we just think that it is just useless inactive blubber sitting on us that will not go away. However, fat is actually quite active and one of the actions it undergoes it to produce the hormone called leptin. So the more fat you have, the more leptin you have.

Leptin is often referred to as the ‘starvation hormone’ , as leptin is supposed to tell the brain that we have enough fat stores, we don’t need to eat and we can keep burning calories at our normal rate. Think back to ancestral times, when things were good, we were being regularly fed and fat stores were up leptin would undergo this action. It then works the other way, so imagine we have no food,  are starving and losing fat mass. The brain picks up that there is much less signalling from leptin due to the smaller amounts of fat we have, triggering the brain to increase our appetite and slow down our metabolism. This will make us eat more and make sure that we do not starve when there is less food going around.

Basically: We eat –> body fat goes up –> leptin goes up –> we eat less and burn more.


We don’t eat –> body fat goes down –> leptin goes down –> we eat more and burn less.

Consequently, you can see that leptin is the hormone in control of how much we eat, how much we burn and how much fat stores we have.

Leptin Resistance – What Is Making Us Fat.

As said before, the more fat you have, the more leptin you will also have. So technically, those who are overweight should be having strong signals from the leptin to stop eating and for their metabolism to be through the roof. However this is not the case, as there is one problem, the leptin signal is not working. So there is a load of leptin floating around, but the brain is not picking up the signal. This is known as leptin resistance and is believed to be one of the major contributors to human obesity.

So when someone has leptin resistance the brain does not pick up the signal from leptin to curb appetite and boost metabolism. It rather thinks that the body is starving, this then cause the brain to increase our appetite and slow our metabolisms right down. This is because the brain thinks that we need to hold on to what we already have since it thinks we are going through a period of starvation.

The problem is that for a lot of people, trying to overcome this hormonal defect through sheer will power is next to impossible.


Why Low-Calorie Diets Do Not Help

Leptin resistance is one of the main reasons that a lot of weight loss programmes do not have long lasting results. This is because despite losing fat mass during a diet, leptin resistance doesn’t necessarily reverse.

Once fat mass and consequently leptin is reduced, the brain initiates the response to increase hunger, decrease motivation to exercise and lower the amount of calories we burn at rest. This is because once we reduce our calories substantially for an extended period of time, body and brain think we are starving and so use powerful mechanisms to try and restore our fat mass and protect us from perceived starvation.

This will be a common situation for many serial dieters; weight loss is easy in the beginning, motivation to exercise is strong. However, that desire to exercise soon diminishes and cravings kick in. This is the main reason behind ‘yo-yo’ dieting where people lose lots of weight in the beginning, only to put it all back on again.

The Cause of Leptin Resistance

The cause of leptin resistance has been identified to come from certain mechanisms:

  1. Inflammation: Inflammatory signalling from the hypothalamus is likely to cause leptin resistance.
  2. Triglycerides: lots of fatty acids floating around in the bloodstream may increase fat metabolites in the brain, which may interfere with leptin signalling.
  3. High Leptin Levels: Having consistently high levels of leptin is likely to cause leptin resistance.
How Do We Reverse Leptin Resistance?

Knowing that you are leptin resistant is pretty simple. If you have a lot of body fat, particularly in the belly area then you are almost certainly leptin resistant.

The key to reversing leptin resistance is to reduce diet-induced inflammation. There are many ways you can do this.

  1. Avoid Processed Food. Processed foods can compromise the integrity of the gut and cause high levels of inflammation.
  2. Eat Soluble Fibre. Eating soluble fibre can help to protect the gut and protect against obesity. Examples of soluble fibre are seeds, nuts and cruciferous vegetables (e.g. broccoli, green beans)
  3. Exercise. Getting plenty of exercise will help to reverse leptin resistance.
  4. Sleep. Poor sleep has been implicated as a factor towards leptin resistance.
  5. Lower Blood Triglycerides: Lowering the amount of fat that you have floating around your bloodstream will help improve the amount of leptin in the blood that can reach the brain. Best way to do this is to reduce your carbohydrate intake.
  6. Eat Plenty of Protein: Eating plenty of protein can cause automatic weight loss. There are many reasons for this, with one potentially being increasing leptin sensitivity.

We have all seen these recommendations before, as they all should make up part of a healthy lifestyle. Leading a healthy lifestyle is the best way to try and reverse this leptin resistance and restore hormonal balance and weight.

People don’t often become obese because they eat copious amounts of foods. It is more of the fact that they eat too much of the wrong foods. Eating the wrong foods has such an effect, because it biologically alters our moods and behaviour.

As a result, leptin resistance is a major factor in why people gain weight and then struggle like hell to lose it. Leptin is the real master of body fat regulation and so needs to be addressed way before how many calories we eat.