How junk food makes your brain want to get fat
Junk food has the advantage that it is fast and generally tasty, but the global industrial diet impairs the function of two hormones, insulin and leptin, which establish a biochemical boost in our brains to eat more than we are supposed to eat.
Leptin is the body’s energy balance hormone.
Leptin is an incredibly important hormone in the body.
It is secreted by our fat cells. The larger they are, the more leptin they secrete.
More fat = more leptin.
Leptin is supposed to send signals to the brain, informing you about the amount of body fat stored.
We eat. Body fat is stored. Leptin increases. The brain “sees” leptin and causes us to stop eating.
This is a basic loop of negative feedback: the output (leptin) decreases the input (eat). This is how the brain is supposed to keep body fat levels within a narrow range in the long term.
The problem today is that leptin is not working.
Obese individuals have high levels of leptin, but it is not reaching the brain, and therefore there is no sign that fat cells have enough stored energy and that the person needs to stop eating.
Insulin boosts fat storage and blocks leptin.
You’ve probably heard of insulin before, and if you consume too much junk food, you may need to read carefully.
It is the hormone secreted by the pancreas after eating a meal with carbohydrates (proteins also affect it, to a lesser extent).
One of the other functions of insulin is that it causes the body to synthesize fats from glucose and then tells fat cells to collect as much fat as they can and store it.
This is one of the reasons why diabetics begin to gain weight when they inject insulin. Insulin takes fat to storage.
In addition to boosting fat storage, insulin blocks leptin signals in the brain.
How to invest in it
If you are already overweight or obese, then you probably already have problems with these two hormones.
Fortunately, the solution is incredibly simple. All you have to do is eat fewer sugars and starches (carbohydrates).
This is the best way to reduce blood insulin levels.
Eating less carbohydrates, so present in junk food (especially fructose), also reduces triglycerides, another known cause of leptin resistance.
If fewer carbohydrates reduce insulin and improve leptin resistance, then they should be effective in reversing obesity, which is what they are.
What about the low-fat and high-carb diets?
The failure of the low-fat diet may be good for thin people, but it is quite useless as a cure, probably because it does nothing to treat the root causes of obesity, including insulin and leptin resistance.
The largest randomized controlled trial ever on the diet, called the Women’s Health Initiative, which included 48,835 postmenopausal women, revealed some interesting results: Women on the low-fat diet were only 0.4 kg lighter than women who consumed the standard American diet after 7.5 years.
This and many other studies show that the standard low-fat diet is highly ineffective.