What are the reasons for not losing weight after 15 days of fasting

It may be related to the metabolic adaptation period, water retention, muscle volume change, irrational diet structure, hormone level fluctuations and other factors. Long term fasting may lead to a decrease in basal metabolic rate, which in turn affects weight loss effectiveness.

1. Metabolic adaptation period

Continuous fasting triggers the body's self-protection mechanism, reducing basal metabolic rate to decrease energy expenditure. When calorie intake is consistently insufficient, the body will prioritize breaking down muscles rather than fat for energy, leading to a halt in weight loss. At this point, it is necessary to adjust the dietary pattern to avoid metabolic damage.

2. Water retention

The increase of cortisol level during fasting may lead to sodium retention, and the increase of water in the body will mask the weight change of fat loss. Especially for women, hormonal changes before and after menstruation are more likely to cause edema, and at this time, the weight scale numbers cannot truly reflect the progress of weight loss.

3. Changes in muscle mass

Long term fasting can cause muscle protein breakdown. Although fat is decreasing, muscle loss may lead to insignificant weight changes. Muscle density is greater than fat, and muscles are heavier under the same volume. A decrease in body fat percentage but no change in weight is also a normal phenomenon.

4. Dietary structure problems

If excessive intake of high salt and high sugar foods, or implicit calorie intake such as seasoning sauces, nuts, etc. is present during the resumption of eating, it may offset the effect of fasting. Some people are sensitive to carbohydrates, and insulin resistance can also affect weight loss efficiency.

5. Fluctuations in hormone levels

Endocrine problems such as thyroid dysfunction and insulin resistance can interfere with fat metabolism. Elevated progesterone levels in women after ovulation can lead to water and sodium retention, and continuous secretion of stress hormones can also hinder fat breakdown. Medical examination should be conducted to rule out pathological factors.

It is recommended to use intermittent fasting instead of long-term fasting. Choose 2-3 days a week for a 16 hour light fasting, and maintain a balanced diet for the rest of the time. Daily intake of sufficient high-quality protein and dietary fiber, combined with resistance training to maintain muscle mass. Regularly measuring body circumference and body fat percentage is more meaningful than simply focusing on weight. If there is no change in weight for more than 3 weeks, medical attention should be sought to investigate potential issues such as thyroid function and insulin sensitivity. Ensuring a daily intake of 2000 milliliters of water and sufficient sleep during weight loss can help regulate the balance of leptin and ghrelin.