Why Starvation Diets Don't Work. Many people turn to starvation diets when trying to lose weight. They drastically reduce calories hoping to lose weight as quickly as possible. They're making a big mistake. A very low calorie diet can produce quick weight loss, but what happens once the diet ends? Most people go back to the same old way of eating that caused them to be overweight in the first place and end up gaining back any lost weight. The reality is that very low calorie diets almost never result in permanent weight loss.