Article Review: Evidence-based Nutrition and Supplements

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EvgeniZyntx
EvgeniZyntx Posts: 24,208 Member
edited March 1 in Food and Nutrition
The abstract has been posted a few times on MFP but I thought it would be useful to look at the recommendations and the overall review article.

While it is not original research Helms et al. published a good review of a set of limits and recommendations that should be of interest for someone losing weight and attempting a body recomposition, quite common on MFP. The article focus is lean individuals preparing for a bodybuilding competition but many of the points covered are in-line with general weight loss, athletic training or recomposition efforts.

However, remember that the context is weight-training individuals reaching lower % body fat.

Article Review: Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation
By Eric R Helms, Alan A Aragon and Peter J Fitschen
The article:
http://www.jissn.com/content/11/1/20
The popularity of natural bodybuilding is increasing; however, evidence-based recommendations for it are lacking. This paper reviewed the scientific literature relevant to competition preparation on nutrition and supplementation, resulting in the following recommendations. Caloric intake should be set at a level that results in bodyweight losses of approximately 0.5 to 1%/wk to maximize muscle retention. Within this caloric intake, most but not all bodybuilders will respond best to consuming 2.3-3.1 g/kg of lean body mass per day of protein, 15-30% of calories from fat, and the reminder of calories from carbohydrate. Eating three to six meals per day with a meal containing 0.4-0.5 g/kg bodyweight of protein prior and subsequent to resistance training likely maximizes any theoretical benefits of nutrient timing and frequency. However, alterations in nutrient timing and frequency appear to have little effect on fat loss or lean mass retention. Among popular supplements, creatine monohydrate, caffeine and beta-alanine appear to have beneficial effects relevant to contest preparation, however others do not or warrant further study. The practice of dehydration and electrolyte manipulation in the final days and hours prior to competition can be dangerous, and may not improve appearance. Increasing carbohydrate intake at the end of preparation has a theoretical rationale to improve appearance, however it is understudied. Thus, if carbohydrate loading is pursued it should be practiced prior to competition and its benefit assessed individually. Finally, competitors should be aware of the increased risk of developing eating and body image disorders in aesthetic sport and therefore should have access to the appropriate mental health professionals.

Calories cuts

Caloric intake should be set at a level that results in bodyweight losses of approximately 0.5 to 1%/wk to maximize muscle retention.
The study recommends that maximum recommended daily calorie cuts should be approximately:

Lbs: Weight/100 * 500 cals/day/lb = X cals/day
Kgs: Weight/100 * 1100 cals/day/kg = X cals/day

Or about 1000 cal cut max for a 200 lb person.

The authors raise concerns with this type of static analysis and mention cuts might need to be larger and adjusted as a person goes in for a longer period of diet due to Metabolic Adaptation/Adaptive Thermogenesis.
(They do recommend a specific text to read further on managing MA/AT - Trexler E, Smith-Ryan A, Norton L: Metabolic adaptation to weight loss: implications for the athlete. - which mentions periodic refeeding, step-wise "reverse dieting", high protein (<+25%), resistance training supporting the general advice often given on the site.)

Proteins
The article presents an interesting overview of protein needs and studies but these are generally better treated in the analysis/review already presented by Sara:
http://www.myfitnesspal.com/topics/show/1158604-eric-helms-protein-research

In summary, authors suggest that "the lower the body fat of the individual [weight training, athletes], the greater the imposed caloric deficit and when the primary goal is to retain LBM, the higher the protein intake (within the range of 2.3-3.1 g/kg of LBM) should be."

Carbohydrates
Carbs tend to be the last consideration when setting macros on MFP (get your protein/get your fat/ then the rest as carbs). The authors highlight the concern that carbohydrates are of primary importance when considering athletic performance. These should be aligned to individual goals and performance needs - Inadequate carbohydrate is reported to impair strength training and consuming adequate carbohydrate is known to reduce glycogen depletion and enhance performance, particularly in people active in endurance activities.
The review mentions two points which I consider worth highlighting:
- a carbohydrate intakes for strength sports, including bodybuilding, be between 4–7 g/kg/day depending on the phase of training
- for individuals that are at or near their desired leanness - a possible increase in carbohydrate of 25-50 g, thereby reducing the caloric deficit by 100-200 kcals in an effort to maintain performance and LBM

Carbohydrate needs of mixed sports and endurance athletes are recognized as being higher than strength athletes and the reader is recommended to review a reference which itself has a reference.... well, to keep it short, 5-7 g/kg/day of carbs seems to fit general training while endurance athletes are probably best served in the 7-10 g/kg/day range.

( Nutrition guidelines for strength sports: Sprinting, weightlifting, throwing events, and bodybuilding http://www.tandfonline.com/doi/abs/10.1080/02640414.2011.574722?url_ver=Z39.88-2003&amp;rfr_id=ori:rid:crossref.org&amp;rfr_dat=cr_pub=pubmed&amp; and http://www.ncbi.nlm.nih.gov/pubmed/11310548)

Fat

One of the weakness of the article is that it focuses the fat discussion primarily on the influence of testosterone production to only come to the conclusions that "the caloric deficit and loss of body fat itself may have a greater impact on testosterone than the percentage of calories coming from dietary fat."

However, some of the points made are worth noting
- "diets too low in fat or too high in protein might impair the hormonal response to training."
- "results might indicate that attempting to maintain resistance training performance with higher carbohydrate intakes is more effective for LBM retention than attempting to maintain testosterone levels with higher fat intakes."
- "Body composition and caloric restriction may play greater roles in influencing testosterone levels that fat intake."
- "testosterone changes in men appear mostly related to energy availability (body fat content and energy balance), and not surprisingly low-levels of sustained energy availability are also the proposed cause of the hormonal disturbance “athletic amenorrhea” in women"

All this suggests that the size of cuts, and the authors agree, should be reduced as the person gets leaner to avoid impacting fat/carb availability.

The authors note "arguments for fat intakes between 20 to 30% of calories have been made to optimize testosterone levels in strength athletes" ..."low carbohydrate diets may degrade performance" or negatively affect hormones that are "closely correlated to LBM preservation than testosterone" and suggest that a lower end fat intake for body builders between 15-20% of calories...can be deemed appropriate, if higher percentages reduce carbs/protein below ideal within a diet.

Nutrient Timing

So, is it important to time meals before and after training to hit the "anabolic window". In short, No.
The article covers this in depth. I'll only note a few highlights:

- "To-date, only a minority of chronic studies have shown that specific timing of nutrients relative to the resistance training bout can affect gains in muscular size and/or strength."
- "In contrast, the majority of chronic studies have not supported the effectiveness of timing nutrients (protein in particular) closely around the training bout."
- "Most recently, a study observed no significant effect on muscle mass and strength from consuming whey protein immediately before or throughout resistance training."
- "In addition to the paucity of studies using ample protein doses, there is a lack of investigation of protein-carbohydrate combinations."

Finally "In the exceptional case of resistance training sessions that approach or exceed two hours of exhaustive, continuous work, it might be prudent to employ tactics that maximize endurance capacity while minimizing muscle damage. This would involve approximately 8–15 g protein co-ingested with 30–60 g carbohydrate in a 6-8% solution per hour of training."

"In terms of practical application to resistance training bouts of typical length, Aragon and Schoenfeld recently suggested a protein dose corresponding with 0.4-0.5 g/kg bodyweight consumed at both the pre- and post-exercise periods. However, for objectives relevant to bodybuilding, the current evidence indicates that the global macronutrient composition of the diet is likely the most important nutritional variable related to chronic training adaptations."

Meal Frequency

A lot of confounding, conflicting and challenging research, in an area that requires much further study, allows the authors to make the following conclusions: "The evidence collectively suggests that extreme lows or highs in meal frequency have the potential to threaten lean mass preservation and hunger control" ... "However, the functional impact of differences in meal frequency at moderate ranges (e.g., 3–6 meals per day containing a minimum of 20 g protein each) are likely to be negligible in the context of a sound training program and properly targeted total daily macronutrition."

Supplements
Of the possible legal supplements, the authors make positive arguments for Creatine, beta-alanine and Caffeine. Other supplements, like BCAA's, Arginine, Citrulline malate, etc... are found to be lacking in long term research, efficacy or safety evaluations.

Enjoy!

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