Dieting to lose weight, the more you lose weight
Now more and more obese patients come to the clinic and say, I don't eat much, or even don't eat every night, I just can't lose it, or even fatter.
In fact, there are many scientific truths in this.
T. Mann reviewed studies of long-term results from a calorie-restricted diet in which obese patients starved an average of 38 days in the hospital and were followed for different periods of time after the starvation period ended.
Of patients followed for 2 or more years, 83 percent rebounded more than they lost weight. Even in the longest follow-up studies (4 or 5 years after dieting), the weight rebound trajectory generally did not level out, suggesting that participants would continue to gain weight if they were followed longer[1].
Not only that, but dieting is very bad for us to lose weight. There are two main reasons.
First: Dieting reduces the basal metabolic rate. Basal metabolic rate refers to the energy metabolic rate of the human body when it is awake and extremely quiet, unaffected by muscle activity, ambient temperature, food, and mental stress [2].
The basal metabolic rate is high, and the more energy you consume each day, the more fat is metabolized, the more conducive to weight loss. One such experiment was conducted last century at the University of Minnesota in Gome. The 32 people were given two meals a day for the first three months, a total of 3200 calories, and after three months, a 6-month hunger experiment was conducted, still two meals a day, a total intake of 1570 kcal energy.
After the experiment, the basal metabolic rate of the volunteers was reduced by more than 40% on average. Due to the decrease in the basal metabolic rate, as long as the diet is normal, the weight will definitely rebound.
Second: Dieting can have an effect on hormones related to weight regulation. Here are two types of related hormones: leptin and ghrelin.
Leptin is a hormone secreted by adipose tissue that acts on receptors located in the central nervous system, and when the content of leptin in the serum increases, it can accelerate metabolism.
Ghrelin is a peptide produced in the stomach that regulates appetite, eating, and when the level of ghrelin increases, it will produce a stronger sense of hunger.
In a study from Camos, SGJA, 82 healthy subjects were selected to follow a very low-energy diet for 8 weeks and measured plasma concentrations of leptin before and after the diet.
Results showed that leptin decreased from 26.9 μg/l before the experiment to 13.9 μg/l at the end of the experiment[3]. Compared with no diet, the concentration of leptin in the serum after dieting will decrease, which means that this metabolism will be reduced, which is not conducive to weight loss.
Studies on the effects of dieting on ghrelin, Cummings, DE, can be confirmed. Thirteen obese subjects were selected for 6 months of dietary control to study the changes in ghrelin in their plasma. The results showed that plasma ghrelin levels rose sharply shortly before two meals and decreased shortly after each meal.
Diet-induced weight loss was 17 percent of the initial body weight, which was associated with a 24 percent increase in ghrelin at 24 hours [4]. This is also the reason why many people want to eat more after dieting.
Also, dieting can leave you with malnutrition. Because there are very few types of things to eat, and the amount is also very small, the natural intake of nutrients is not enough. Malnutrition leads to wasting and reduced resistance, which increases the risk of infectious diseases.
Improper dieting, especially long-term low-carbohydrate diet, can damage nerve cells in the brain. A study of mice in Pediatr Res pediatrics showed that mice with inadequate carbohydrate intake had significantly impaired visual spatial learning and memory compared with rats fed a conventional diet [5].
Dieting can bring many factors that are detrimental to weight loss. So, the body is smarter than you think, dieting to lose weight will only get fatter.
In the short term, you will lose weight, but in the long run, fat will be easier to accumulate. If you don't eat enough, you have the strength to lose weight, or there is still a certain scientific reason. #Obesity# #吃药, dieting, exercise, which weight loss method works the fastest##Weight loss##Nutrition#
bibliography:
[1] Mann T , Tomiyama A J , Westling E , et al. Medicare's search for effective obesity treatments: diets are not the answer. [J]. American Psychologist, 2007, 62(3):220-33.
Lü Haihong. New Laboratory Manual of Endocrine and Metabolic Diseases: Gansu Nationalities Publishing House, 2016: 25
[3] Camps, S. , Verhoef, S. , & Westerterp, K. R. . (2015). Leptin and energy restriction induced adaptation in energy expenditure. Metabolism-clinical & Experimental, 64(10), 1284-1290.
[4] Cummings D E , Weigle D S , Frayo R S , et al. Plasma ghrelin levels after diet-induced weight loss or gastric bypass surgery. [J]. N Engl J Med, 2002, 346(21):1623-1630.
