Almost all weight loss experts believe that the main cause of obesity is eating too much and not burning it off. Conversely, a reasonable diet with proper exercise, and no excess calories converted to fat, means there will be no obesity problem. For example, the United States is the country with the most obese people in the world, while in famine-stricken countries like Ethiopia, obese people are a rare sight.
For a long time, human society has been fighting against hunger. An empty stomach and a famished face, with basic malnutrition, naturally leave no room for good health. This concept has long been deeply ingrained.
However, overeating and having a big belly, with an excess of junk food in the body, is also a sign of being unhealthy. It not only involves changes in lifestyle but is also related to people's concepts of health.
Compared to the past, our standard of living has improved, and our diets have become more varied and colorful. But now that we have plenty to eat, people are getting fatter, and "rich man's diseases" such as cardiovascular and cerebrovascular diseases and diabetes are on the rise. In response, Professor Hong Zhaoguang, a national expert in cardiovascular disease research, pointed out that this is not the fault of material civilization, but rather a result of insufficient spiritual civilization and outdated health concepts.
In fact, mild hunger is beneficial to health. A common saying goes, "Always keep a little hungry, and eat until you are seven-tenths full." The health-preserving philosophy of Li Yu, a writer from the Ming Dynasty, was that "the degree of hunger and fullness should not exceed seven-tenths." The reason is that "eating twice as much damages the stomach and intestines." Furthermore, according to Professor Roy Walford of the University of California, Los Angeles, between 1991 and 1993, he and seven colleagues lived in isolation for two years in the "Biosphere 2" project in the Arizona desert. They meticulously recorded the changes in the scientists' physical conditions after reducing their food intake: the average weight of the four men decreased by 18%, and the average weight of the four women decreased by 10%. The average blood pressure of the eight scientists decreased by 20%, and their blood sugar and insulin levels decreased by an average of 30%. The cholesterol levels of the eight individuals dropped from an average of 195 to "extremely healthy and normal 125."
Mild hunger also contributes to longevity. Scientists have conducted similar experiments on rats in laboratories. They let one group of experimental rats eat their fill, while they halved the food intake of another group. As a result, the semi-starved rats were in much better physical and mental condition than the well-fed rats, with healthier hearts, stronger immunity, more vigorous reproductive abilities, and a 70% longer lifespan. Research on obesity shows that among people of the same height, the heavier they are, the higher their mortality rate and the shorter their lifespan; conversely, among non-smokers of the same height, the lighter they are, the lower their mortality rate and the longer their lifespan. Because smaller food intake helps them avoid the chronic toxicity of food, they have fewer chances of contracting serious illnesses. Additionally, lighter individuals place less burden on their hearts, allowing them to enjoy a long life.
Today, as human material life gets better and better, there is more and more food available. The development of technology has also made activities that once required a lot of physical exertion now require much less. People's caloric needs have changed significantly compared to decades ago. Therefore, for many people, three meals a day may not necessarily be a healthy eating pattern. The feeling of hunger people get at mealtime is often more of a conditioned response rather than a true physical need.
As for why mild hunger leads to health and longevity in animals, Professor Nelson of the University of Texas Health Science Center explained that cell death is a major factor in aging, and mild hunger can stimulate the body's potential to save cells from death. Consequently, he further suggested that those who usually overeat might consider regularly skipping one meal a day or reducing the amount of food at each meal.