HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Electronic Letters to:

EXERCISE AND MUSCLE: S. Nissen, R. Sharp, M. Ray, J. A. Rathmacher, D. Rice, J. C. Fuller, Jr., A. S. Connelly, and N. Abumrad Effect of leucine metabolite -hydroxy--methylbutyrate on muscle metabolism during resistance-exercise training J Appl Physiol 1996; 81: 2095-2104 [Abstract] [Full text] [PDF]

eLetters: Submit a response to this article

Electronic letters published:

HMB and protein

Louise T Gottsche   (14 March 2008)

HMB and protein 14 March 2008
Louise T Gottsche, Dietician PVM Nutritional Sciences Send letter to journal: Re: HMB and protein louise{at}pvm.co.za Louise T Gottsche	Dear authors Thank you for taking the time to publish your study. Yet I have a few questions? You describe that you have had 6 groups: - Low protein diet with no HMB - Low protein diet with 1.5g/d HMB - Low protein diet with 3.0g/d HMB - High protein diet with no HMB - High protein diet with 1.5g/d HMB - High protein diet with 3.0g/d HMB Yet, you report only 5 groups in your results. Do I understand correctly: Did you combine the 0g/d, 1,5g/d, 3g/d HMB groups following low and high protein diets when you report on 0g/d, 1,5g/d, 3g/d HMB. Did you then compare the low protein diet with 0g HMB with the high protein diet with 0g HMB to report on protein intake? I am not sure whether this results will provide me with answer as to whether it is HMB or protein that are responsible for your results. HMB is a metabolite of leucine. If you ensure a high protein diet (say shake with whey protein which are high in leucine)will you not achieve the same results than adding HMB? I know leucine may follow various pathways, but still- will a high protein diet not also lower muscle proteolysis to the same extend than HMB. ALternatively, will a high protien diet with a lower HMB intake (say 1g/d) also achieve these results. Futhermore, it seems that results are dose-dependant, but will a lower HMB dosage have any effect? With regards to the protein intakes. Your high protein diet also had a higher energy content. Generally a higher energy content will result in a higher body weight. Yet in your study you did not find this to be the case. Is it possible that the energy difference is not great enough to achieve results. You alos did not compare individuals with themselve to account for individaul BMR variations. The constant weight, despite higher energy intake may also be due to the thermogenic effect of protein. I think if you would have liked to compared high versus low protein intakes, you should have kept the total energy intake constant and just vary the ratio of protein versus carbohydrates.