Un apport constant de protéines tout au long de la journée est préférable contre la graisse et pour les muscles
Are there health benefits associated with distributing protein intake equally across meals in older adults?
Samaneh Farsijani Appl. Physiol. Nutr. Metab. 2015 Vol. 40, p510
Recent evidence showed that an even distribution of protein intake
across meals (30/30/30g) compared to a typically skewed distribution
(11/16/63g) over 7 days results in greater muscle protein
synthesis, in young adults. Whether these results translate into
preservation of lean mass in the long-term and if these apply to
older adults experiencing muscle loss remains unknown. We aimed
to investigate the association between protein intake pattern at
baseline (T1), with body composition and muscle function in a large
cohort of senior adults at T1 and over 3-year follow-up. Methods:
Secondary data analysis from the Quebec Longitudinal Study of
Nutrition and Successful Aging (NuAge) in 1793 communitydwelling
healthy men and women aged 68-82 years. Food intake
was assessed from 3x24h-food recalls; body composition from
circumferences, skinfold thickness and DXA (T1&T3;); muscle
strength and physical performance from handgrip strength, 4mwalking
speed, chair stand, one-leg standing balance, timed Up&Go;
and physical activity (PASE questionnaire).
Preliminary results: The average protein intake for breakfast, lunch and dinner was 16±8,
27±14 and 35±15g for men (n=827), and 12±6, 24±11, 28±12g for women
(n=914). Men with EVEN versus UNEVEN protein intake (33±10% of
total/meal, n=88, versus >33±10%) had lower %body fat at T1 and T3
and arm skinfold thicknesses from T1-T4 (p<0.05 at each T). Analyses
were controlled for total protein and energy intake, age and PASE.
Men also had greater bone mineral content at T1 and T3 (p<0.05,
p<0.07 controlled). Women with EVEN (n=104) had lower %body fat
than UNEVEN (37±1.2 vs. 40±0.4%, p<0.05) only at T3. EVEN was associated
with greater 4m-walking speed (p<0.05) and muscle strength
(p<0.08 controlled); other functional tests and lean mass index did not
differ. Differences in changes over time appeared constant between
groups.
Conclusion: Protein intake in these older participants is not as
skewed as in US younger adults (NHANES) but is definitely lower at
breakfast. An even protein distribution was associated with less adiposity,
better bone health and certain muscle function tests but was
not related to lean mass or losses over time, where total protein intake
may play a predominant role.
