Why Diets Don’t Work

The main recommendation given by many experts for weight loss is usually the same: low-fat hypo-caloric diet. It all comes down to the famous formula:

Weight variation = calories ingested – calories expended

But according to some studies, 90-95% of the people who try to lose weight with this strategy fail. “What happens to people that follow a diet in the long run?”. “Would they have gotten to a better result if they didn’t follow a diet at all? We decided to dig up and analyse every study that followed ‘people on diets’ for two to five years. We concluded that most of them would have been better off not going on the diet at all. Their weight would be pretty much the same, and their bodies would not suffer from losing weight and gaining it all back again.” (Dieting does not work, UCLA researchers report)

Along the same lines, this study concludes that ONLY restricting calories is physiologically inappropriate for weight loss.

I mean, the idea of controlling calories has been a failure. We all know people who achieved it, but they are the minority (the 5-10% who, according to studies, achieve it).

The problem is that it does not give us useful information about how our body really works and what actions to take to achieve weight loss.

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Weight loss

If a person is obese, this obviously means that they have ingested more calories than they have expended, but then again, saying that something is obvious does not help us solve the problem.

We must go further: If your body asks for more calories (hunger) and uses less energy, we must understand why it does that. And the only answer with the current approach is ‘lack of will’.

I want to start by clarifying that nobody has all the answers. Obesity is a beast with many heads, but instead of continuing to promote useless information and blaming people for their lack of will, we must look for plans that are closer to the real way in which our body works.

Why is the Current Model failing?

The current approach to counting calories sees the body as a passive organism, as a closed system that consumes energy and expends energy, and where each one of us can voluntarily act on these energy flows, basically eating (energy input) or with physical activity (output power).

This leads to the widely publicized notion that all foods are good, and you just have to watch your portions. This reinforces the idea that to maintain (or lose) weight we must simply count calories. But this approach has serious problems.

This model does not optimize the type of weight you lose (or gain). Losing weight by destroying muscle is a bad idea. The type of weight matters, a lot.

Our body has many ways of altering its energy expenditure beyond voluntary physical activity, which is the only variable in which we tend to center.

The body is not a passive system with a fixed expense. If you modify the energy it receives, or its energy reserves (fat), you need to understand what is happening and adjust appropriately. Your body is always in survival mode, it doesn’t care about how you look in the mirror.

Losing Weight Involves Biological Factors

The “energy regulator” of the of our body is the hypothalamus, and what many scientific studies tell us is that it has its own idea of ​​what the ‘ideal weight’ is (which does not usually coincide with yours).

Besides an ideal weight, what the hypothalamus defends is a range of energy available (fat): the so-called set point. By slightly altering the calories going in and out, you will be able to move within this narrow range without much problem. However, if you try to modify this in a stronger way, the hypothalamus will resist, displaying those powerful biological factors.

The main system that controls your weight management is called adipostat, can be equated to a thermostat. If you think about your home thermostat, its goal is to maintain the same temperature even when external conditions change. If you open a window the thermostat makes the necessary adjustments to maintain the temperature. In the same way, if you modify the energy you give or the energy that you require the body to use, your thermostat adjusts other factors that influence your weight.

Understanding the Adipostat

There are many hormones and chemical signals that participate in this complex regulatory system, but to make it simple we could say that the leaders of the group are two: leptin and the hypothalamus.

The first one tells your brain that you have enough energy stored in your fat cells to engage in normal, relatively expensive metabolic processes

The hypothalamus responds to this information using multiple tools, the most relevant being appetite and energy expenditure. When leptin indicates that the reserves are low, it responds with cravings for food (to motivate you to look for food) and with the reduction of metabolism to preserve energy (less desire to move, lower body temperature, etc), until it regains a level of fat with which you feel ‘calm’.

The hypothalamus continues to do what it has done for millions of years: maximize the chances of survival.

Part of the adipostat is defined by genetics, but another part is modifiable. Studies points towards the fact that over the last decades something has changed in our environment that has affected this advanced regulatory system, and this resulted in a higher resistance to leptin.

When sensitivity to leptin is lost, receptors in the brain require increasingly higher levels of leptin to understand that you have enough fat. In other words, the body has to scream louder for the brain to hear it. You have accumulated energy to spare, but your brain keeps thinking that you don’t.

The result is that the set point is raised. Now that extra 5 or 10 kilos becomes the new “desirable” level of fat for your hypothalamus, the level that it will defend with all its power.

Why Does the Rebound Effect Occur?

When you follow a diet, the weight loss becomes clear in the first 6 months. Faced with an energy deficit, the body is forced to burn reserves, but why does the rebound effect occur?

The reason is that when you put your body under caloric deficit, your metabolism slows down. It is one of the powerful weapons of the hypothalamus, which results in even “turning off” certain non-vital systems to reduce consumption.

When you lose 10% of your weight caloric expenditure is significantly reduced, and this effect is maintained even after returning to the original weight. Studies proved this effect by measuring the levels of leptin and the thyroid hormones, which are the main agents that control metabolism.

Therefore: If go back to eating the same amount of calories that you did before your diet, since now you have a slower metabolism, your body will accumulate more fat than before.

The rebound!


Usually, the body will start to regulate itself and in a few weeks / months will return to the normal weight. All the sacrifice would have been in vain, and you may have damaged your hormonal environment or developed new fat cells that will never go away. . Repeating this process of lowering and bouncing continuously ends up taking its toll, and studies indicate that the body responds worse with each new ‘attempt’. Your body becomes slower to lose weight and faster to gain it.

Sometimes doing nothing is better than doing something wrong.

So, What Should I Do?

In the battle between hunger and will, hunger wins. Always. Any approach that relies primarily on cutting calories without controlling hunger is bound to fail. You will be able to hold out for a while, but in the end you will give up. The kilos will return (with an extra gift due to the rebound effect) and your chances of achieving your goal in the next attempt will be reduced.

What is our best option to decrease the fat body? Basing your diet on real, non-industrial food, and eating until you are full.

This does not imply that it is not a good idea to record the calories you consume for a while and understand the percentages in which you eat your macro nutrients (Carbs, Proteins and Fats). Firstly because calories and macronutrients matter, and secondly because it allows you to learn how your body responds to certain changes. But counting calories / macros as an indefinite weight management tool is not the solution.

Some Recommendations
  • Eat more protein, more vegetables, and foods in general with high nutritional density.
  • Eat enough protein. In addition to satiety, protein mitigates the metabolic adaptations produced by losing weight.
  • Reduce triglycerides, as it is speculated that they may interfere with the entry of leptin into the brain. How? Lowering carbohydrates, especially refined ones.
  • Reset your leptin every now and then, including higher carb (and calorie) days if you’re on a low-carb diet. Don’t feel guilty about the occasional cheat meal! The frequency of this depends a lot on each case. And every now and then, give yourself a week or two off.
  • Do not cut calories by limiting too much fat, because this further slows down metabolism. Another typical problem of conventional low-calorie diets.
  • Avoid snacks. Metabolism slows down from not eating to satiety day after day, not from going three hours without eating. Low-calorie diets that distribute food in many small amounts often achieve the opposite effect of what they are intended to do.
  • Try an intermittent fasting strategy. Getting your body used to not receiving calories every so often helps it better regulate its energy levels, also reducing anxiety.
  • Less variety. Although it sounds weird, bombarding your brain with many different flavors makes it difficult to lower the set point. For a while it is convenient to reduce the variety of your diet, which is not a problem if it’s good quality food.
  • Adjust your training to mitigate these adaptations.

Losing weight is always difficult, but if the latest science and practical experience tell us there are better tools, let’s use them!

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Published by marciacoronado0698

I’m Marcia, I’m from Argentina, currently living in Sydney, Australia. I few years ago I started my fitness journey, and shared my experience through social media.

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