Most people cram most of their daily protein into their evening meal, and consume relatively little protein at breakfast and lunch. If all three meals contain similar amounts of protein, the synthesis of muscle tissue increases by a quarter, according to a study published in the Journal of Nutrition.
Honestly speaking, we thought about it carefully, whether we were going to bother to write an article about the study that Madonna Mamerow, of the university of Texas, published in the June edition of the Journal of Nutrition. The conclusions have a pretty high Captain Obvious content, especially for the readers of this webzine.
On the other hand, the article is interesting because it flies in the face of studies that have shown that pulsed administration of proteins has an anabolic effect. In those studies, proteins stimulated the synthesis of muscle tissue in – not so healthy – over sixties better when the researchers gave the proteins in pulsed portions rather than concentrated all together. Read more about protein pulsing here and here.
The protein pulse concept is popular within the intermittent fasting movement, but regarded as controversial by the rest of the world. The jury is still out among scientists, because a study that used people in their twenties as subjects, suggests that protein pulses actually seem to have no anabolic effect.
Mamerow’s eight subjects were aged between 25 and 55. On one occasion they were given breakfast containing 10 g protein, lunch with 15 g and an evening meal with 65 g protein, every day for a week. [SKEW] So in total they consumed 90 mg protein a day.
On another occasion they were given breakfast containing 30 g protein, lunch with 30 g and an evening meal with 30 g protein every day for a week. [EVEN] So with the more evenly distributed protein the subjects also consumed 90 g a day.
When Mamerow measured the amount of protein the subjects made in their muscles [FSR], she saw that the synthesis was 25 percent higher over the whole day during the EVEN week compared with the SKEWED week.
“The consumption of a moderate amount of high quality protein 3 times a day provides a more effective means of stimulating 24-h muscle protein synthesis than the common practice of skewing protein intake toward the evening meal”, the researchers conclude.
Dietary Protein Distribution Positively Influences 24-h Muscle Protein Synthesis in Healthy Adults.
Abstract
The RDA for protein describes the quantity that should be consumed daily to meet population needs and to prevent deficiency. Protein consumption in many countries exceeds the RDA; however, intake is often skewed toward the evening meal, whereas breakfast is typically carbohydrate rich and low in protein. We examined the effects of protein distribution on 24-h skeletal muscle protein synthesis in healthy adult men and women (n = 8; age: 36.9 ± 3.1 y; BMI: 25.7 ± 0.8 kg/m(2)). By using a 7-d crossover feeding design with a 30-d washout period, we measured changes in muscle protein synthesis in response to isoenergetic and isonitrogenous diets with protein at breakfast, lunch, and dinner distributed evenly (EVEN; 31.5 ± 1.3, 29.9 ± 1.6, and 32.7 ± 1.6 g protein, respectively) or skewed (SKEW; 10.7 ± 0.8, 16.0 ± 0.5, and 63.4 ± 3.7 g protein, respectively). Over 24-h periods on days 1 and 7, venous blood samples and vastus lateralis muscle biopsy samples were obtained during primed (2.0 ?mol/kg) constant infusion [0.06 ?mol/(kg?min)] of l-[ring-(13)C6]phenylalanine. The 24-h mixed muscle protein fractional synthesis rate was 25% higher in the EVEN (0.075 ± 0.006%/h) vs. the SKEW (0.056 ± 0.006%/h) protein distribution groups (P = 0.003). This pattern was maintained after 7 d of habituation to each diet (EVEN vs. SKEW: 0.077 ± 0.006 vs. 0.056 ± 0.006%/h; P = 0.001). The consumption of a moderate amount of protein at each meal stimulated 24-h muscle protein synthesis more effectively than skewing protein intake toward the evening meal.
PMID: 24477298 [PubMed – in process] PMCID: PMC4018950
