There is a tendency to believe that changes in body weight are due solely to the calories consumed vs. those that are expended.
Current studies have refuted this theory. They have made it clear that weight gain or loss processes are closely related to the effects of a hormone called leptin. (1,2,3)
Leptin is a hormone capable of regulating the desire to eat and staying satisfied. When a person has uncontrolled levels, they feel like eating at all times. For this reason, it is also known as the hunger hormone.
When the body does not respond to this hormone, it has leptin resistance. Research claims it is one of the leading causes of excess fat in humans (3).
This article summarizes how to avoid leptin resistance and what are the effects of this hormone on body weight gain.
How does leptin work?
Thanks to leptin, the brain receives information about how much body weight is and how much energy is stored in fat stores¹.
Leptin is supposed to alert the brain when necessary to continue eating (or not) based on body fat a person has. The primary role of the hormone leptin is to regulate energy in the long term.
It also participates in the immune and nervous systems (5). Leptin works by stimulating a particular area of the brain: the hypothalamus.
The rise and fall of hunger hormone levels is a method that evolved over the years to prevent humans from starving. Today, these processes are altered: leptin resistance is one of the most common disorders in urban populations. (5.6)
What is leptin for:
- Long-term energy regulation
- Suppressor whet your appetite
- Participates in immune functions
- Of importance, infertility processes
Leptin resistance and body weight
When a person has a chronic high level of leptin, they develop leptin resistance; the brain stops detecting fat stores and sends the wrong hunger signals.
A person with leptin resistance feels the urge to eat, even when they have already ingested enough calories. For this reason, leptin resistance is said to be closely associated with increased body weight.
Studies consider leptin resistance to be one of the leading causes of overweight and obesity. (1,2)
Causes and consequences of leptin resistance
Leptin resistance can appear due to eating disorders, extreme diets, genetic causes, sedentary lifestyles, and excess sugar.
Fat cells produce leptin in proportion to their size, obese people have a lot of fat in their cells, so they also have high levels of leptin.
When eaten, the percentage of body fat increases, leading to increased leptin production.
On the contrary, body fat decreases when you eat less, and your leptin levels go down. This system is known as a feedback system.
When a person gives positive feedback to the system (eats more and more), they develop leptin resistance and enter a complex cycle to get out. The consequences: uncontrolled weight gain.
However, leptin resistance is reversible. It takes time, perseverance, and professional assistance. Eliminating sugars from the diet is one of the first steps to preventing its long-term consequences.
Leptin amount – men vs. women
The amount of leptin in women’s bodies is usually up to 2-3 times that of men.³ For this reason, women are more likely to tend to be resistant to leptin.
The difference between leptin levels between men and women could explain why there is a difference in body fat between both sexes. (5)
Although there are still more studies to confirm this fact, it has become clear that controlling leptin levels is essential to regulating body weight.
How to reverse leptin resistance?
To reverse leptin resistance, the diet must be based on an abundance of foods with plant fiber ; (green vegetables, whole grains, bran), lean meats, and cheeses; and a source of healthy vegetable fats: ( olive oil, rapeseed, coconut, chia).
The consumption of sweet foods (with added white sugar) and industrial products that include sodium glutamate should be limited as much as possible.
Starting with a low-impact physical activity like walking is the first step in reversing leptin resistance. In addition, studies have shown that leptin increases with the stress hormone cortisol. (9) So, avoiding or controlling stressful situations can be a fundamental step in reversing resistance.
Effects of diets on leptin levels
If an overweight person begins a diet with a firm refusal of food or with a calorie restriction greater than 20, it can cause drastic changes in leptin levels.
In response to this, the body of a person with leptin resistance tries to somehow compensate for its lack. One of its consequences can be robberies or an impulsive desire to eat for short periods. (5)
People with leptin resistance try to lose weight with strict diets or a rapid and robust food refusal.
An excellent method to eliminate body fat must be able to maintain the results over time. For this, it is best to do the process step by step. Delete simple carbohydrates, and start moving is essential to regulate leptin levels.
The keto diet has been shown to increase leptin levels. Studies (7,8) do not recommend extending it to avoid leptin resistance for more than 12 months.
The hormone leptin is a crucial regulator of appetite and a feeling of fullness, as it is this hormone that informs the body about the presence of fat deposits. Chronically high levels of leptin disrupt metabolism, leading to the development of diabetes mellitus and concomitant obesity. Unfortunately, most reduced-calorie diets only exacerbate this mechanism.
Leptin is one of the essential hormones in regulating body weight. When a person has leptin resistance, they feel like eating. The causes of this phenomenon are multifactorial; It is believed that excessive sugar consumption may be one of the main factors.
Leptin levels in women are higher than in men, which could justify why the female sex accumulates more fat.
Leptin resistance is reversible. However, carrying out specific diets such as the keto diet can cause opposite effects. The best way to reverse leptin resistance is to eat a low-calorie diet with complex carbohydrates as your primary energy source.