A diet is a regulated amount of food that is used to decrease, maintain or increase body weight. A diet combined with physical exercise is popular to lose or maintain body weight. The focus of diets is typically on weight loss. These diets usually fall into one of four categories: low-fat, low carbohydrate, low calorie or very low calorie. The first popular diet was named the “Banting” after William Banting in the 1860s and consisted of low carbohydrate and low calorie food.
Some diets are not safe, nor are they healthy. Many long-term studies have shown that usually those who dieted ended up regaining nearly all or all of the weight that was once lost. This is even in cases where the diet was maintained. One health detriment to those who diet consistently is that the mortality rate may slightly increase. Other side effects from dieting may include: lowered metabolism, depression, fatigue, low sex drive, fainting, irritability, seizures, constipation and dehydration. There can also be substantial damage done to internal organs, depending on the diet.
One major controversy among diets is low carbohydrate versus low fat – which is better? Some diets are favorable for potential reduction in heart disease and Type II diabetes. Another controversy is with very low calorie diets as they subject the body to starvation and have many adverse side effects. Another controversy is with fasting – is it safe to fast and how long to fast? Many health professionals believe that lengthy fasting can lead to the risk of malnutrition and should only be carried out with medical supervision.