Healthvit Fitness L - Leucine Leucine Is Largely Considered The Prime Amino Acid Responsible For Protein Synthesis (Muscle Growth) And Can Be Used Directly By The Body For Energy When Under Stress. Leucine Can Also Assist Regulating Blood Sugar Levels So Can Be Beneficial When Dieting. Roles Of Leucine In The Dieting :- L- Leucine Stimulates Muscle Protein Synthesis And Absorbs Quickly, Causing Leucine Levels In The Blood To Rise Quickly. Leucine Has Also Been Explored As A Fat-Loss Drug. When You Restrict Your Calories, Some Of The Weight You Lose Can Come From Muscle Mass, Which Can Slow Your Progress. L- Leucine Has Also Been Explored As A Fat-Loss Drug. When You Restrict Your Calories, Some Of The Weight You Lose Can Come From Muscle Mass, Which Can Slow Your Progress. Muscle Requires Energy To Exist, So It Burns Calories, Even When You're Sitting Still. Fat Is Just Dead Weight.