Whenever your dieting demands a lot of willpower, you are risking your success. Having to fight against your inner survival system is hard work and not pleasant at all, and the longer you continue, the more likely it is that you fall off the wagon. Many diet plans take this into account and suggest “free days”, when you get to eat anything you want to, to make it easier to continue on the diet. In other words, you only have to suffer for six days a week and the seventh is for resting (or whichever the system). This might work for some people, but is not the best long term solution. It can also lead to unnecessary binge eating on the free days.
Another good reason for the “free days” is to avoid the energy saving mode your body will turn itself into, if you keep your calorie intake too low for a longer period. The body doesn’t know you are trying to lose weight, and it starts to protect you from your diet instead. If that happens, your weight stalls and you would have to eat even less to keep losing weight.
Many low-calorie diets are about different ways to eat very little but try to make it seem like you were eating more. Short diets are about will-power: you get fast results if you can handle being hungry for three-four days. In both cases, you will end up being hungry. If you really want to go through a short diet, there are some things to do to make it a bit easier to succeed. Clean up your cupboards and make sure there are no temptations at home. Go shopping before the diet and stay away from groceries and malls while on the diet. Make plans and keep yourself busy for the duration of the diet. Short diets can be a good solution if you want to lose weight fast just before a special event.
Low-calorie diets are often high in carbohydrates and low in fat, which makes sense calorie-wise: fat has nine calories in a gram whereas carbohydrates have only four! But what would you say if I told you that carbohydrates are the only macro-nutrients which can cause weight gain? If you are gaining weight, it’s very likely that your body has problems with processing high amounts of carbohydrates (remember, we are evolutionally still in the past where we didn’t have refined carbohydrates around every corner), and if that is the case, you can gain weight even on a low-calorie diet, if the calories come mostly from carbs.
Carbohydrates make you hungry as well. High carbohydrate loads raise the blood glucose level, and the pancreas will secrete insulin to get it back to normal. Insulin is very effective and fast. It gets the blood sugar level back to normal and usually even below, making us hungry right after eating. Protein and fat keep you satisfied for longer, and the people on a low-carbohydrate, high-fat diet report not being hungry at all even if they have chosen to limit their calorie intake.