Moderate energy restriction with high protein diet results in healthier outcome in women

Abstract

BackgroundThe present study compares two different weight reduction regimens both with a moderately high protein intake on body composition, serum hormone concentration and strength performance in non-competitive female athletes.MethodsFifteen normal weighted women involved in recreational resistance training and aerobic training were recruited for the study (age 28.5 ± 6.3 yr, height 167.0 ± 7.0 cm, body mass 66.3 ± 4.2 kg, body mass index 23.8 ± 1.8, mean ± SD). They were randomized into two groups. The 1 KG group (n = 8; energy deficit 1100 kcal/day) was supervised to reduce body weight by 1 kg per week and the 0.5 KG group (n = 7; energy deficit 550 kcal/day) by 0.5 kg per week, respectively. In both groups protein intake was kept at least 1.4 g/kg body weight/day and the weight reduction lasted four weeks. At the beginning of the study the energy need was calculated using food and training diaries. The same measurements were done before and after the 4-week weight reduction period including total body composition (DXA), serum hormone concentrations, jumping ability and strength measurementsResultsDuring the 4-week weight reduction period there were no changes in lean body mass and bone mass, but total body mass, fat mass and fat percentage decreased significantly in both groups. The changes were greater in the 1 KG group than in the 0.5 KG group in total body mass (p < 0.001), fat mass (p < 0.001) and fat percentage (p < 0.01). Serum testosterone concentration decreased significantly from 1.8 ± 1.0 to 1.4 ± 0.9 nmol/l (p < 0.01) in 1 KG and the change was greater in 1 KG (30%, p < 0.001) than in 0.5 KG (3%). On the other hand, SHBG increased significantly in 1 KG from 63.4 ± 17.7 to 82.4 ± 33.0 nmol/l (p < 0.05) during the weight reducing regimen. After the 4-week period there were no changes in strength performance in 0.5 KG group, however in 1 KG maximal strength in bench press decreased (p < 0.05) while endurance strength in squat and counter movement jump improved (p < 0.05)ConclusionIt is concluded that a weight reduction by 0.5 kg per week with ~1.4 g protein/kg body weight/day can be recommended to normal weighted, physically active women instead of a larger (e.g. 1 kg per week) weight reduction because the latter may lead to a catabolic state. Vertical jumping performance is improved when fat mass and body weight decrease. Thus a moderate weight reduction prior to a major event could be considered beneficial for normal built athletes in jumping events.

The Effects of Intensive Weight Reduction on Body Composition and Serum Hormones in Female Fitness Competitors

“…Third, resistance and aerobic training have been shown to attenuate the loss of lean mass during energy deficit when compared to energy restriction alone (Kraemer et al, 1999; Miller et al, 2013), which were both also used during the diet by the present fitness competitors. Moreover, the changes in body weight of the diet group were rather slow, on average ~0.4 g/kg per week, which is actually pretty close to the level that was previously observed to maintain lean mass in normal-weight females on a diet (Mero et al, 2010) and what has been recommended for fat loss in fitness diets (Helms et al, 2014). The average participant, while resistance trained, had not had many years of training experience (average 3.5 ± 1.4 years in the diet group and 3.1 ± 1.2 years in the controls), which makes it possible for some to even gain some muscle mass on a diet when regularly conducting resistance training combined with high protein intake (Josse et al, 2011; Longland et al, 2016).…”

High Resistance Training Volume and Low Caloric and Protein Intake Are Associated with Detrimental Alterations in Body Composition of an Amateur Bodybuilder Using Anabolic Steroids: A Case Report

“…As a consequence, hypertrophic pathways may be impaired. Therefore, we would follow previous suggestions to losẽ 0.5 kg of body mass per week in order to promote body mass reduction without activating catabolic pathways [20,21], which seems to be attainable with a caloric restriction of 300-750 kcal per day [21]. This reduction in caloric intake should be accompanied by a protein intake of around 1.2 to 2.0 g/kg, as has been previously suggested for bodybuilders [6,22].…”

Nutritional Recommendations for Physique Athletes

“…By manipulating the length of contest preparation (and, therefore, the rate of weight loss), the size of the energy deficit can be modified to influence the degree of acute Journal of Human Kinetics -volume 71/2020 http://www.johk.pl relative energy deficiency. For example, Mero et al (2010) investigated the effects of two different rates of weight loss in recreationally trained females on protein-matched (1.4 g/kg) diets. One group was assigned to lose 1 kg per week (with an energy deficit of 1100 kcal/day), while the other was assigned to lose 0.5 kg per week (with an energy deficit of 550 kcal/day).…”