Influence of Fish Oil-Derived n-3 Fatty Acid Supplementation on Changes in Body Composition and Muscle Strength During Short-Term Weight Loss in Resistance-Trained Men

Abstract

Background: A detrimental consequence of diet-induced weight loss, common in athletes who participate in weight cutting sports, is muscle loss. Dietary omega-3 polyunsaturated fatty acids (n-3PUFA) exhibit a protective effect on the loss of muscle tissue during catabolic situations such as injury-simulated leg immobilization. This study aimed to investigate the influence of dietary n-3PUFA supplementation on changes in body composition and muscle strength following short-term diet-induced weight loss in resistance-trained men. Methods: Twenty resistance-trained young (23 ± 1 years) men were randomly assigned to a fish oil group that supplemented their diet with 4 g n-3PUFA, 18 g carbohydrate, and 5 g protein (FO) or placebo group containing an equivalent carbohydrate and protein content (CON) over a 6 week period. During weeks 1–3, participants continued their habitual diet. During week 4, participants received all food items to control energy balance and a macronutrient composition of 50% carbohydrate, 35% fat, and 15% protein. During weeks 5 and 6, participants were fed an energy-restricted diet equivalent to 60% habitual energy intake. Body composition and strength were measured during weeks 1, 4, and 6. Results: The decline in total body mass (FO = −3.0 ± 0.3 kg, CON = −2.6 ± 0.3 kg), fat free mass (FO = −1.4 ± 0.3 kg, CON = −1.2 ± 0.3 kg) and fat mass (FO = −1.4 ± 0.2 kg, CON = −1.3 ± 0.3 kg) following energy restriction was similar between groups (all p > 0.05; d: 0.16–0.39). Non-dominant leg extension 1 RM increased (6.1 ± 3.4%) following energy restriction in FO ( p < 0.05, d = 0.29), with no changes observed in CON ( p > 0.05, d = 0.05). Dominant leg extension 1 RM tended to increase following energy restriction in FO ( p = 0.09, d = 0.29), with no changes in CON ( p > 0.05, d = 0.06). Changes in leg press 1 RM, maximum voluntary contraction and muscular endurance following energy restriction were similar between groups ( p > 0.05, d = 0.05). Conclusion: Any possible improvements in muscle strength during short-term weight loss with n-3PUFA supplementation are not related to the modulation of FFM in resistance-trained men.

High-Protein Energy-Restriction: Effects on Body Composition, Contractile Properties, Mood, and Sleep in Active Young College Students

“…The two group, parallel research design was adapted from Mettler et al ( 2010 ) and Philpott et al ( 2019 ) and is illustrated in Figure 1 . Once the participants were pair-matched using the variable muscle mass divided by body mass, they were randomly assigned ( randomizer.org ) to either the energy restriction group (ER, n = 14) or the eucaloric control group (CG, n = 14).…”

Lean mass sparing in resistance-trained athletes during caloric restriction: the role of resistance training volume

“…With respect to the studies' abstracts, 51 of the reviewed studies were chosen to be potentially relevant for data analysis. The full texts of these articles were then screened; 36 of these studies (Greene et al 2018;Helms et al 2015b;Mero et al 2010;Newton et al 1993;Sawyer et al 2013;Tinsley et al 2017;Trabelsi et al 2013Trabelsi et al , 2012Vargas et al 2018;Walberg-Rankin et al 1993;Waldman et al 2018;Kleiner et al 1990;Bamman et al 1993;Hickson et al 1990;Withers et al 1997;Wilson et al 2017;Chatterton et al 2017;Durguerian et al 2016;Murphy and Koehler 2020;Gentil et al 2017;Steen 1991;Manore et al 1993;Too et al 1998;Moro et al 2016;Areta et al 2014;Kysel et al 2020;Philpott et al 2019;Huovinen et al 2015;Antonio et al 2019;Bazyler et al 2018;Mäestu et al 2008Mäestu et al , 2010Dudgeon et al 2016;Mettler et al 2010;Rossow et al 2013;Syed-Abdul et al 2019) were excluded from analysis for various reasons. Thus, 15 studies were used for qualitative analysis.…”

The Effects of a 6-Month High Dose Omega-3 and Omega-6 Polyunsaturated Fatty Acids and Antioxidant Vitamins Supplementation on Cognitive Function and Functional Capacity in Older Adults with Mild Cognitive Impairment

“…Regarding the procedures underlying these improvements, the exact molecular mechanisms that mediate improved skeletal muscle mass and functionality with omega fatty acid intake and/or in combination with specific vitamins (as in the present formula used) have not been fully elucidated. The most-commonly proposed mechanism to underpin the anabolic action of PUFA is via the incorporation of EPA/DHA and LA/GLA into the membrane phospholipids of the sarcolemma and intracellular organelles as well as at the cell membranes at the inflammation sides [35,67,68]. Furthermore, the presence of the specific antioxidant vitamins can modulate the overall positive effect by limiting the presence of the free radicals (both reactive oxygen species (ROS) and reactive Nitrogen species (RNS) as a result of the ongoing oxidative stress which can potentially affect muscle function and age-related sarcopenia [35,69].…”

“…Furthermore, the presence of the specific antioxidant vitamins can modulate the overall positive effect by limiting the presence of the free radicals (both reactive oxygen species (ROS) and reactive Nitrogen species (RNS) as a result of the ongoing oxidative stress which can potentially affect muscle function and age-related sarcopenia [35,69]. This structural change of the muscle membrane may activate intracellular signaling proteins (e.g., mTORC1-p70S6k1) that upregulate muscle protein synthesis, thus modulating muscle mass [26,67,68]. The positive effects on muscle function could also be related to the proposed beneficial effects of PUFAs on mitochondrial and neuromuscular function.…”