Low-carb diets help you shed pounds rapidly in the first few weeks, but you aren't magically dropping fat. A reduction in carbohydrates and an increase in protein causes your body to lose excess water weight naturally. Carbohydrates actually encourage your body to hold on to water, so the more carbs you eat, the more water you retain.
The Institute of Medicine recommends that you get 45 to 65 percent of your daily calories from carbohydrates, which are found primarily in breads, pasta, grains, starchy vegetables and sugars. Diets at the upper end of this recommendation, or in excess of it, clearly qualify as high in carbs. Endurance athletes often follow a high-carb diet of up to 70 percent carbs prior to competition to increase the energy stores in their muscles. Some high-carb diets are promoted for weight loss and health, including the low-fat Ornish Diet, as well as the McDougall Program for Maximum Weight Loss, in which Dr. John McDougall proposes that you get more than 80 percent of your calories from carbs. Some classify the standard American diet as high in carbs and unhealthy because it contains mostly processed, refined grains and added sugars.
Body in Balance
When you consume carbohydrates, your body converts them to glycogen, which is then stored in the muscles for energy. For every gram of glycogen stored, you gain approximately 2.7 grams of water. This water retention occurs because your kidneys hold on to sodium in response to carbohydrate consumption. Your body reacts to the higher sodium levels by storing more water to keep the sodium-blood concentration at a healthy level.
Lose It with Lower Carbs
Restricting carbohydrates reduces your glycogen stores and allows the kidneys to excrete water more readily, resulting in weight loss. When you reduce carbs, your protein and fat intake automatically increases as a percentage of calories consumed, and both of these nutrients encourage water loss. Many carbohydrate foods are dense sources of calories. When you eat fewer of these, you usually end up cutting your total calorie intake, which also leads to weight loss.
Carbs Are Not All Bad
The proclivity of carbohydrates to cause water retention doesn't make them the enemy. Consumed in moderation, healthy carbohydrates, such as those in whole grains, potatoes and fruits, provide you with energy and important vitamins and minerals. While cutting out refined carbohydrates can reduce your weight and improve your overall health, you don't need to cut out carbohydrates altogether.