There was a study on suppversity that showed BCAAs during exercise/dieting helped preserve LBM, but slowed fat loss as well. Just throwing that out there. I can link it if its allowed.
A write up on the results of that study vs the click bait that some online science sites like to post:
The best physiologically possible body composition outcome for an individual performing resistance training while intentionally trying to lose body fat through restricting calories is to maintain their pre-diet muscle mass while losing fat mass. Very few athletes who often cut weight (e.g. MMA, boxers, wrestlers, dancers, etc.) are able to lose body fat without simultaneously losing muscle mass. These athletes often maximize muscle mass and muscular performance (e.g. power, strength) gains in the off-season as they know that they will lose a significant amount of muscle mass and muscular performance as they cut their body weight to achieve their target performance weight. A very low calorie supplement that could help these athletes maintain their hard earned muscle mass and muscular performance gains while still cutting body fat would be the ideal product to use for any person that is trying to gain or maintain their muscle mass and muscular performance.
The results from an independent university-based study showed that supplementation of Scivation’s Xtend in experienced weight trained athletes performing resistance training while on a caloric-restricted diet allowed the subjects to maintain their pre-diet muscle mass and preserve skeletal muscle performance while simultaneously losing fat mass.
The subjects using Scivation’s Xtend maintained their muscle mass while the subjects that used the placebo lost nearly 2 pounds of muscle mass. The subjects supplementing with Scivation’s Xtend lost 1.1 pounds of body fat while the subjects on the placebo didn’t have a significant change in body fat.
Performance wise, subjects using Xtend had a 3X greater increase in their lower body muscular performance (i.e. back squat) over the placebo subjects. In addition, the Xtend group significantly increased bench press strength by over 15 pounds while the placebo group lost over 8 pounds of muscular strength.
During caloric restriction the body’s typical response is to utilize available energy sources, both lipid and muscle, to provide the necessary calories for survival. So, to be able to maintain lean tissue mass and lose fat mass during caloric restriction is a near ideal outcome.