Probably the vast majority takes one or another diet sometimes , but do not manage to lose weight at all. If you do not know what prevents losing weight you should have a look at this list of enemies of diet.
Saturated or trans fats. There are so many products that contain these fats, including dairy products (such as yogurt), and precooked products. Always give priority to natural products.
Artificial sugar substitutes. They slow down the metabolic rate, increase the need for sugar and forces you to consume more calories. Remember that almost all soft drinks contain artificial sweeteners.
Flour. It doesn’t have much useful substances but lots of calories. Flour slows down your metabolism, and accumulates energy in extra centimeters and kilograms. Avoid cakes, pastries and other similar products, or at least try to replace them with full-grain flour and oat bran products.
Salt. Salt retains body fluids and slows down weight loss. Just add less salt to your meals.
Starch based products (potatoes, rice). First of all they slow down your metabolism. They have lots of simple carbohydrates, which the body tends to reserve and transform into fats later.
Ketchup. It contains a lot of sugar and salt, so it is better to refuse it.
Mayonnaise. Even tiny amounts of salad with mayo make a product quite high in caloreis. In addition, it has a lot of trans-fats, preservatives, salt and sugar, which, were already mentioned as an obstacle to losing weight.