How much weight can I lose in a week on a low carb diet?

When dieters make a decision to lose weight, they want to see results quickly. Low-carb diets have proven popular for their fast initial results. Current research supports the effectiveness of low-carb for weight loss, especially during the first few months. Weight loss during the first week may not be significant. However, the two popular low-carb diets, Atkins and South Beach suggest you can lose almost 7 kg (about 15 lbs) in the first two weeks. The National Health Service, though, warns that low-carb diets tend to be high in saturated fats, which can actually promote the development of heart disease.

Low-carb method

The basic premise of the low-carb diet is that by limiting your intake of carbs, a major energy resource for the body, you cause your body to burn fat for fuel, in a process called "ketosis". Low-carb diets severely reduce your intake of carbohydrates from foods, such as breads, pasta, sugar, fruit and starchy vegetables, in favour of low-carb foods like meat, eggs, nuts and non-starchy vegetables.

Diet phases

Two popular low-carb diets, Atkins and South Beach, work in phases, with the first phase having the least amount of carbs and usually the greatest weight loss. Phase one in Atkins, called Induction, is two weeks long and cuts carbs down to 20 grams a day. The Atkins program reports you can lose about 7 kg (15 lbs) during the induction phase. The first phase in South Beach lasts three weeks. During this phase, all grains, fruits and starchy vegetables are avoided. Dr. Arthur Agatston, M.D. author of "The South Beach Diet" tells his readers that they can expect to lose between 3.5 kg and 6 kg (about 8 and 13 lbs) within the first two weeks, and up to a kilogram a week in the later phases.

Weight loss

Both Atkins and South Beach report significant losses within two weeks. Reports by dieters suggest that, while a few pounds are lost during the first week, the largest losses come during the second week of the initial phase. Both Stanford University and the Mayo Clinic in the U.S. suggest that initial first week weight loss is due to calorie restrictions more than reducing carbs. A 2005 study in the "Annals of Internal Medicine", supported the calorie-reduction theory, but indicated that carbs were the culprit in overeating. By reducing carbs, dieters in the study automatically reduced their calorie intake by 1,000 without feeling hungry. An additional kilogram could be lost from water weight. It isn't until the body makes the adjustment to ketosis, which usually takes from three to five days, according to Dr. Atkins, that you can be sure you're burning fat weight from a low-carb diet.


Low-carb diets are not meant to be a week long, quick weight loss plan. The fast initial results can jump start your diet and motivate you to eat well, but the strict phase one eating plan isn't designed for long-term dieting. Both Atkins and South Beach add healthy complex carbs back into the diet during later phases. This slows weight loss down, but ensures you're getting important nutrients and fibre. Both Atkins and Agatston recommend eating lean proteins and healthy fats like olive oil to maintain heart health. Also, stay hydrated by drinking lots of water. Ketosis helps burn fat for fuel, but it can lead to dehydration and related health issues without adequate hydration.

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About the Author

Leslie Truex has been telecommuting and freelancing since 1994. She wrote the "The Work-At-Home Success Bible" and is a career/business and writing instructor at Piedmont Virginia Community College. Truex has a Bachelor of Arts in psychology from Willamette University and a Master of Social Work from California State University-Sacramento. She has been an Aerobics and Fitness Association of America certified fitness instructor since 2001.