It's different now. The poor are just a little short of money, but they can basically solve their own food and clothing problems. Many poor people eat first for their own economic situation, mainly to fill their stomachs, without thinking too much about nutrition. And many cheap foods are basically fattening foods. Most of the cheaper ingredients on the market belong to high-carbon water food. After the human body ingests these foods, it is easy to store energy in the body, thus making people fat.
What's more, many poor people spend most of their lives occupied by other things. They don't have much free time to spend on sports and fitness. Many poor people are passive in sports and seldom take the initiative to exercise. Without exercise, their metabolism will slow down and their weight will increase.