Carbohydrates serve as your body's preferred fuel source for everything from exercising to completing mental tasks. When you follow a low-carbohydrate diet, the goal is to control your carb intake to encourage your body to utilize stored fat for energy. Because your body stores carbohydrates for later use, there's a short lag time between when you start your low-carb diet and when you start burning fat for energy.
A wide variety of foods contain carbohydrates, including fruits, vegetables and grains. Once you consume a carb-containing meal, your body converts the carbs to glucose and stores them in your muscles and liver in the form of glycogen. Your body has a limit to how much glycogen it can store and maxes out at about 2,000 calories of carbohydrates. This is equivalent to about 500 grams, most of which is stored in your muscles while about 90 to 110 grams is stored in your liver.
On a typical low-carb diet, it may take two to three days for your body to use up glycogen stores and switch to using fat as a primary fuel source, according to Jonny Bowden, author of "Living Low Carb."
Whether or not a low-carb diet is beneficial in the long run is a controversial topic, and not all medical researchers agree. A low-carb diet limits otherwise healthy foods such as fruits and whole grains, which may make it more difficult to get a balanced amount of vitamins, minerals and other vital nutrients. Limiting carbohydrates typically leads to an increase in the amount of fat in your diet and a decrease in fiber. Studies demonstrating the long-term benefits are necessary.
Even though a low-carb diet doesn't restrict the number of calories you eat, it's still crucial that you control your portions and have balanced meals, according to Bowden. This means choosing fish, tofu, chicken breast, lean cuts of beef and pork and other lean protein sources, says Bowden. The typical low-carb diet allows somewhere between 60 and 130 grams of carbohydrates a day, so it's necessary to balance meals with nonstarchy vegetables like asparagus, broccoli, brussels sprouts, cauliflower, leafy greens and eggplant.
Low-Carbohydrate Menu Ideas
It's crucial to keep your carb intake consistent and remain within your allotted amount of carbs each day so that you continue to burn fat. Cheating with a high-carb meal may interfere with weight loss. Planning your meals ahead of time helps increase your chances of sticking to the diet, according Bowden.
A low-carb breakfast idea is an asparagus and goat cheese omelette made with 1/2 cup of asparagus and four egg whites. Have healthy snacks to prevent cravings. A midmorning snack idea is 4 ounces of plain, low-fat yogurt with a handful of almonds. A sample lunch is homemade chilli using 99-percent lean ground beef or turkey. For a midafternoon snack, try 4 ounces of low-fat cottage cheese with 3.5 ounces of blackberries. A low-carb dinner example is grilled shrimp tossed with 1 cup of zucchini and 1/2 cup of broccoli.
- Iowa State University: Carbohydrates
- Living Low Carb: Controlled-Carbohydrate Eating for Long-Term Weight Loss; Jonny Bowden, Ph.D.