What Causes This? No Matter How Much I Eat, I Don’t Increase in Size.

There are several potential reasons why someone may not increase in size despite eating a lot:

High metabolism: Some people naturally have a higher metabolism, which means their body burns calories more quickly. This can make it difficult to gain weight even when consuming a lot of food.

Poor absorption: Some medical conditions can affect the body’s ability to absorb nutrients from food, such as celiac disease, inflammatory bowel disease, or other gastrointestinal disorders. This can lead to malabsorption and difficulty gaining weight.

Underlying medical condition: Certain medical conditions, such as hyperthyroidism, can cause weight loss despite adequate caloric intake.

Physical activity: If you have a very active lifestyle, you may be burning more calories than you are consuming, leading to difficulty gaining weight.

Genetics: Genetics can also play a role in body size and shape, and some people may have a naturally slim build.

If you are concerned about your inability to gain weight, it may be worth speaking to a healthcare professional or a registered dietitian who can help determine the underlying cause and provide advice on how to achieve a healthy weight. They may recommend certain dietary changes, exercise routines, or medical treatments to help you reach your goals.