A time‐efficient reduction of fat mass in 4 days with exercise and caloric restriction

Abstract

To determine whether a fast reduction in fat mass can be achieved in 4 days by combining caloric restriction (CR: 3.2 kcal/kg body weight per day) with exercise (8-h walking + 45-min arm cranking per day) to induce an energy deficit of ∼5000 kcal/day, 15 overweight men underwent five experimental phases: pretest, exercise + CR for 4 days (WCR), control diet + reduced exercise for 3 days (DIET), and follow-up 4 weeks (POST1) and 1 year later (POST2). During WCR, the diet consisted solely of whey protein (n = 8) or sucrose (n = 7) (0.8 g/kg body weight per day). After WCR, DIET, POST1, and POST2, fat mass was reduced by a mean of 2.1, 2.8, 3.8, and 1.9 kg (P < 0.05), with two thirds of this loss from the trunk; and lean mass by 2.8, 1.0, 0.5, and 0.4 kg, respectively. After WCR, serum glucose, insulin, homeostatic model assessment, total and low-density lipoprotein cholesterol and triglycerides were reduced, and free fatty acid and cortisol increased. Serum leptin was reduced by 64%, 50%, and 33% following WCR, DIET, and POST1, respectively (P < 0.05). The effects were similar in both groups. In conclusion, a clinically relevant reduction in fat mass can be achieved in overweight men in just 4 days by combining prolonged exercise with CR.

Exercise Preserves Lean Mass and Performance during Severe Energy Deficit: The Role of Exercise Volume and Dietary Protein Content

“…A full description of our study population and general procedures has been published previously (Calbet et al, 2015). The general characteristics of the 15 overweight volunteer participants are summarized in Table 1.…”

Physiology of leptin: energy homeostasis, neuroendocrine function and metabolism

“…Circulating leptin levels decrease in overweight men after negative energy balance is achieved with exercise and calorie restriction, indicating that leptin levels reflect energy status [59]. Low leptin levels during fasting trigger metabolic and hormonal responses in mice and humans [11, 60], consisting of hyperphagia, hypogonadotropic hypogonadism, and suppression of thyroid and growth hormone (GH) levels, which are prevented by physiologic doses of leptin [7, 61, 62] (Fig.…”

“…A negative energy balance achieved in 4 days by combining calorie restriction and exercise in obese subjects resulted in a rapid decline in leptin, indicating that changes in leptin levels reflect energy balance [59]. Human skeletal muscle expresses low levels of LepRb.…”

Restrição calórica e suplementação com leucina no destreinamento físico: parâmetros lipídicos e de sensibilidade à insulina no fígado

“…Dentre essas intervenções, a restrição calórica tem um papel de destaque uma vez que a sua aplicação acompanhada ou não do treinamento físico, demonstra efeitos positivos na redução do peso corporal, melhora no perfil lipídico e na sensibilidade à insulina, dentre outros benefícios que contribuem para o aumento da longevidade em humanos e animais (BORDONE; GUARENTE, 2005;CALBET et al, 2014;CAVA;FONTANA, 2013;ERIKSSON;TAIMELA e KOIVISTO, 1997;MERCKEN et al, 2012;RAVUSSIN, 2011;REDMAN et al, 2009).…”

“…Entretanto, em alguns casos a restrição pode atingir valores superiores a esses mencionados (CALBET et al, 2014;MERCKEN et al, 2012;NICKLAS et al, 2015). Inicialmente a restrição calórica age provocando um desequilíbrio no balanço energético em decorrência da menor oferta energética, resultando na perda de peso.…”