CICO diet (Calories In, Calories Out)

This diet works because it's based on the fundamental law of energy balance. Calories go in through the food you eat then go out when it's used as fuel for your physical activities. Then, if you consume more calories than you use, you gain weight. If you consume fewer calories than you use, you lose weight. If the calories you consume is the same amount as what you use, then you maintain weight.

The main benefit of this diet is that it works for EVERYONE. This can be proven by the common experience of people that when they eat a lot, they generally gain weight, especially if they're not physically active. On the other hand, you eat too little, then you lose weight regardless. However, it must be noted that the starvation diet does not just lead to weight loss but can also lead to muscle loss and nutrient deficiency.

In terms, of weight management, what you eat does not matter as long as you match your calorie consumption and calorie use to your goals. But keep in mind that you need to eat enough protein to retain muscle. It is recommended that people eat about 1 gram of protein per pound of body weight per day to retain muscle. Junk food is also welcome in terms of weight management, however, nutrient deficiencies can result from doing this for too long. To avoid nutrition deficiency, ensure that about 80% of the food you eat is unprocessed. You can eat carbohydrates, sugar, and fat, as long as it is packed with the needed micronutrients while the calories are accounted for. It would also be a good bonus to do weight training to help with calorie expenditure and muscle gain.