A very interesting piece of research has recently been published by the American Journal of Clinical Nutrition.  The aim of the study was to look at body weight regained after dieting and compare it, in terms of its composition, to the body weight originally lost.

The trial analysed and compared body composition of 78 postmenopausal women before dieting, immediately after and then at 6 and 12 month intervals.

They found that for every 1 kg of fat lost as a result of the diet, 0.26 kg of muscle was lost.  However, for those participants who put on weight after the diet for every 1 kg of fat regained over the following year, only 0.12 kg of muscle was regained.

In terms of percentages, 76% of weight lost was originally from fat.  However, 93% of the weight regained was in the form of fat.

So not only is it likely that dieters end up getting fatter in the longer term, they also lose muscle.  Similar observations have been seen in other studies.

Obviously we don’t want to be gaining more fat but losing muscle is also not good for our long term health goals. Having a healthy muscle mass is important for maintaining metabolic rate (the more muscle we have the more calories we burn at rest – even while we are asleep or watching TV). So if you lose muscle your metabolism slows down which in the long term will make it even harder to maintain a healthy weight.

Good muscle mass is also important for keeping us looking toned and a ‘nice shape’. If you lose muscle then the ability to achieve this is lost.  

Long term, decreased muscle mass can leave us weaker and more prone to injury.

So for successful weight management we want to be focusing on reducing fat mass but at the same time maintaining or increasing muscle mass. We also want to managing our weight with a long term healthy eating strategy rather than a ‘diet’ which, once stopped, means fat piles back on.

Research has shown that having a higher protein intake whilst dieting can help maintain muscle relative to weight loss.  Weight bearing exercise is also important for this.

Fat (not muscle) loss is very much the focus of In2shape.  Body composition is measured regularly to ensure muscle mass is maintained at the same time as losing fat.  This is something that bathroom scales alone can't tell you.  The eating plan on In2shape also ensures the correct amounts of protein in order to support this.

1. Beavers K.M., et al. Is lost lean mass from intentional weight loss recovered during weight regain in postmenopausal women? Am J Clin Nutr. 2011; 94(3):767-774.
2. Mojtahedi M.C., et al. The Effects of a Higher Protein Intake During Energy Restriction on Changes in Body Composition and Physical Function in Older Women. J Gerontol A Biol Sci Med Sci. First published online July 27, 2011.
3. Newman A.B. et al. Weight change and the conservation of lean mass in old age: the Health, Aging and Body Composition Study. Am J Clin Nutr 2005; 82(4):872-8.
4. Farnsworth E. et al. Effect of a high-protein, energy-restricted diet on body composition, glycemic control, and lipid concentrations in overweight and obese hyperinsulinemic men and women. American Journal of Clinical Nutrition 2003; 38(1): 31-39.
5. Layman D.K. et al. A Reduced Ratio of Dietary Carbohydrate to Protein Improves Body Composition and Blood Lipid Profiles during Weight Loss in Adult Women. The American Society for Nutritional Sciences 2003; 133:411-417.