Calcium and Dairy Acceleration of Weight and Fat Loss during Energy Restriction in Obese Adults

TLDR

Low dietary calcium increases adipocyte Ca²⁺ influx, promoting lipogenesis and fat accumulation, whereas higher calcium intake suppresses these effects and accelerates fat loss during caloric restriction in mice. The study aimed to assess whether increasing dietary calcium during caloric restriction enhances weight and fat loss in obese adults. A 24‑week, randomized, placebo‑controlled trial enrolled 32 obese adults on a 500‑kcal/day deficit diet, assigning them to a standard diet (400–500 mg calcium), a high‑calcium diet (800 mg), or a high‑dairy diet (1,200–1,300 mg). Both high‑calcium and high‑dairy regimens markedly increased weight loss (by 26 % and 70 % respectively) and fat loss (by 38 % and 64 % respectively), with the high‑dairy diet producing the greatest effect and shifting a larger proportion of fat loss to the trunk region.

Abstract

Increasing 1,25-dihydroxyvitamin D in response to low-calcium diets stimulates adipocyte Ca2+ influx and, as a consequence, stimulates lipogenesis, suppresses lipolysis, and increases lipid accumulation, whereas increasing dietary calcium inhibits these effects and markedly accelerates fat loss in mice subjected to caloric restriction. Our objective was to determine the effects of increasing dietary calcium in the face of caloric restriction in humans.We performed a randomized, placebo-controlled trial in 32 obese adults. Patients were maintained for 24 weeks on balanced deficit diets (500 kcal/d deficit) and randomized to a standard diet (400 to 500 mg of dietary calcium/d supplemented with placebo), a high-calcium diet (standard diet supplemented with 800 mg of calcium/d), or high-dairy diet (1200 to 1300 mg of dietary calcium/d supplemented with placebo).Patients assigned to the standard diet lost 6.4 +/- 2.5% of their body weight, which was increased by 26% (to 8.6 +/- 1.1%) on the high-calcium diet and 70% (to 10.9 +/- 1.6% of body weight) on the high-dairy diet (p < 0.01). Fat loss was similarly augmented by the high-calcium and high-dairy diets, by 38% and 64%, respectively (p < 0.01). Moreover, fat loss from the trunk region represented 19.0 +/- 7.9% of total fat loss on the low-calcium diet, and this fraction was increased to 50.1 +/- 6.4% and 66.2 +/- 3.0% on the high-calcium and high-dairy diets, respectively (p < 0.001).Increasing dietary calcium significantly augmented weight and fat loss secondary to caloric restriction and increased the percentage of fat lost from the trunk region, whereas dairy products exerted a substantially greater effect.