Total Meal Replacement Diets Effective for Weight Loss, But Can Lead to Bone Loss Interview with:
Radhika Seimon, PhD
Research Fellow at the University of Sydney
Amanda Salis, PhD – Professor of Obesity Research at the University of Sydney
Senior Research Fellow
National Health and Medical Research Council of Australia What is the background for this study?

Response: Total meal replacement diets are severely energy-restricted diets that involve replacing all or almost all foods with nutritionally replete meal replacement products such as shakes, soups, or bars (i.e. total diet replacement).

They are the most effective dietary treatment for obesity, resulting in greater short- and long-term weight loss compared with conventional food-based diets. However, there are concerns that total meal replacement diets may adversely affect body composition, notably lean mass and bone mineral density. What are the main findings?

Response: We conducted a randomized clinical trial comparing the effects of a total meal replacement diet with a conventional food-based diet in postmenopausal women with obesity. While the total meal replacement diet induced almost twice as much weight and fat loss over 12 months compared with the conventional food-based diet, and approximately 1.5 times as much loss of lean mass, the loss of lean mass was proportional to the total amount of weight lost, and there was no adverse effect of either diet on muscle strength.

However, there was an approximately 2.5-fold greater loss of total hip bone mineral density with the total meal replacement diet compared to the conventional diet, and this difference was not accounted for by the greater weight loss. What should readers take away from your report?

Response: While total meal replacement diets are an effective tool for weight and fat loss in people with obesity, caution is necessary when implementing these diets in postmenopausal women, especially in those with osteopenia or osteoporosis (reduced bone mineral density), for whom concurrent bone-strengthening treatments (for example, muscle strengthening exercises) are recommended. However, the current trial should not discourage the use of total meal replacement diets as a treatment for obesity in postmenopausal women, where the loss in bone mineral density must be considered in light of the beneficial effects of substantial weight loss on other health outcomes. What recommendations do you have for future research as a result of this work?

Response: Further investigation is needed to determine the long-term consequences of the associated loss of bone mineral density on health outcomes such as osteoporotic fractures, and to determine how bone mineral density losses could be prevented in postmenopausal women during and after total meal replacement diets. Is there anything else you would like to add?

Response: Radhika Seimon reported serving on the Nestlé Health Science Optifast VLCD advisory board. Amanda Salis reported owning 50% of the shares in Zuman International, which receives royalties for books she has written and payments for presentations at industry conferences; receiving presentation fees and travel reimbursements from Eli Lilly and Co, the Pharmacy Guild of Australia, Novo Nordisk, the Dietitians Association of Australia, Shoalhaven Family Medical Centres, the Pharmaceutical Society of Australia, and Metagenics; and serving on the Nestlé Health Science Optifast VLCD advisory board from 2016 to 2018.


Seimon RV, Wild-Taylor AL, Keating SE, et al. Effect of Weight Loss via Severe vs Moderate Energy Restriction on Lean Mass and Body Composition Among Postmenopausal Women With Obesity: The TEMPO Diet Randomized Clinical Trial. JAMA Netw Open. Published online October 30, 20192(10):e1913733. doi:10.1001/jamanetworkopen.2019.13733


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Last Updated on November 1, 2019 by Marie Benz MD FAAD