When people start a weight loss diet, many lose weight initially then stall. Why is this? Your body stores energy as fat and glycogen. Whereas fat stores can vary dramatically from person to person, your body can only store so much energy as glycogen. Glycogen requires water to be stored. In the initial stages of diet/caloric restriction and exercise, your body depletes these glycogen stores (it needs the glycogen for energy.. its the bodies first go to source), reducing your bodyweight from the elimination of both the weight of the stored glycogen and the weight of the water. Note that nowhere in this process is the much-desired loss of fat! hence the saying that the initial weight loss is water loss. For every gram of glycogen stored, you store anywhere from 3-4 grams of water with it. Carbohydrates which are the initial source of the glycogen when eaten, if they are not needed for immediate energy use they are then stored as glycogen and if these cells are full as fat. On most calorie controlled diets the amount of carbohydrate you consume is significantly reduced, so the body resorts to the stored glycogen as its first energy source, releasing the attached water. Its also why many people have a shock if they have an off diet day and eat a diet rich in carbohydrates and suddenly put on a couple of pounds overnight. If you reduce your calories by 2000 calories a week, the first 2 weeks some people if they have a lot of weight to lose can lose up to 10llbs. If they continue with reducing their diet by 2000 calories per week, over the next two weeks they may only lose 1 or 2lbs since a pound of fat contains approximately 3500 calories.
If you continue with your 2000 calories a week reduction, while initially you will see a reduction in weight loss and fat reduction, this will slowly slow down since weight loss is not linear. This linear assumption does not take into account the bodies natural mechanisms that kick in, with less calories being consumed the body becomes more efficient and learns to survive on less calories. Depending on the overall composition of your diet, if your body has depleted it stores of glycogen and then fat it will start looking to protein as its fuel source, individuals will start to lose muscle mass as the body breaks down muscle tissue to use as its protein source.
When losing weight its very important to take a good multi vitamin since the guidelines of 2000 calories per day also ensures that you obtain the required amount of vitamins and minerals to stay in good health.
Also don’t overestimate how many calories your body actually needs. Every person will have an individual calorie requirement, if you have a smart watch many of these will now tell you how many calories per day you have burned based on your Basic Metabolic Rate ( BMR) and what movement/ sports it has calculated that day. Looking at my results over the last month I burn just under 2000 calories per day, but that includes jogging twice a week, spin class once a week and daily dog walks, if you don’t exercise you may naturally need less calories per day.