According to British scientists, to lose weight, we lose an average of 31 years of life, and still at our own appearance, we have claims. The effects of any diet will not be permanent unless the old habits replace the new ones. Know 10 rules that will keep you in shape all year round. Popular diets such as Dukan, Atkins or low fat are not a good idea for two reasons. First, by eliminating or limiting whole food groups, we can cause nutritional deficiencies. Second: the restrictive approach to Nutrition tends to end in a yo-yo effect.