In real life, many people eat a lot but don’t gain weight. There are many reasons for this, such as congenital genetic factors or acquired diseases that cause this.
First of all, genetics is the most common reason why both parents’ body size affects their offspring to some extent.
Second, the body suffers from certain diseases, especially digestive diseases, such as peptic ulcer, enteritis, irritable bowel syndrome, etc., which cause malabsorption of food and nutrients in the gastrointestinal tract, and although the food intake is high, the digestion and absorption function is not good and the nutrients are not fully utilized.
Metabolic diseases such as diabetes, hyperthyroidism, and cachexia increase the basal metabolism to consume nutrients too fast, even though the nutrients are digested and absorbed, they are quickly consumed by metabolism and cannot be stored by the body and the phenomenon of eating more but not gaining weight occurs.
Some people who stay up all night and are overly stressed and anxious may also have an increased basal metabolism and poor absorption of nutrients, which can lead to a lack of weight gain.