Most of the reasons why people appear to gain weight in middle age are considered to be caused by a variety of reasons, such as the mental stress brought by work and life, which leads to a significant change in their diet and lifestyle habits, a decline in basal metabolism, and a decrease in testosterone levels. However, not everyone will get fat. 1. Dietary habits: Middle-aged people, due to the stress of life, often form bad eating habits such as eating fast food, overeating, meat intake, excessive carbohydrates, coupled with the inevitable consumption of alcohol when socializing, which will lead to the accumulation of fat. 2. Lifestyle habits: Middle-aged people spend less time on physical activities, which contributes to their fat accumulation. 3. Decrease in basal metabolism: After reaching middle age, the decline in physical fitness and the metabolic capacity of internal organs will cause a decrease in the body’s ability to break down fat, and the basal metabolic rate will decrease day by day, causing the accumulation of subcutaneous fat. 4. Decrease in testosterone level: testosterone can increase muscle strength and change the thickness of muscle fibers, low testosterone level after middle age, the risk of diabetes or obesity will be greater. At present, middle-aged people fat is a big trend, want to prevent middle-aged people fat, it is necessary to adjust their own diet and living habits, pay attention to diet light, do not overeat, exercise diligently.