NUTRITION – PROTEIN – LOSING WEIGHT – AGING


3 RESEARCH ARTICLES


Note: Postprandial means after eating a meal


WHEY PROTEIN PRESERVES POST MEAL MPS DURING SHORT-TERM ENERGY RESTRICTION IN OVERWEIGHT AND OBESE ADULTS – 2015


Amy J Hector, George R Marcotte, Tyler A Churchward-Venne, Caoileann H Murphy, Leigh Breen, Mark von Allmen, Steven K Baker, Stuart M Phillips
BACKGROUND:
– Higher dietary protein during weight loss results in a greater loss of fat mass and retention of muscle mass
OBJECTIVE:
– Determine how different sources of proteins (soy or whey) during short-term (14-d) hypoenergetic diet affected MPS and lipolysis
METHODS
– Men (n = 19) and women (n = 21) (age 35–65 y) completed a 14-d controlled hypoenergetic diet (-750 kcal/d)
– Participants were randomly assigned, double blind, to receive twice-daily supplements of:
(a) isolated whey (27 g/supplement) providing a total protein intake of 1.3 ± 0.1 g/(kg/d); 80 kg or 176 lbs = 104 g PRO
(b) soy (26g/supplement), providing a total protein intake of 1.3 ± 0.1 g/(kg/d)
(c) or isoenergetic carbohydrate (25 g maltodextrin/supplement) resulting in a total protein intake of 0.76 0.1 g/(kg/d)
RESULTS
(1) Preintervention, MPS was stimulated more with ingestion of whey than with soy or carbohydrate
(2) Postintervention, postabsorptive MPS decreased similarly in all groups
(3) Postprandial MPS was reduced by 9±1% with whey, which was less than reduction in soy and carb groups (28±5% and 31±5%), respectively
(2) Lipolysis (breakdown of fats) was suppressed during postprandial period but more so with carbohydrate than soy or whey
CONCLUSION:
– Whey protein supplementation attenuated (reduced) decline in postprandial rates of MPS after weight loss


HYPOENERGETIC DIET-INDUCED REDUCTIONS IN MPS ARE RESTORED WITH RESISTANCE TRAINING AND BALANCED DAILY PROTEIN IN OLDER MEN – 2015


Caoileann H. Murphy , Churchward-Venne , C.J. Mitchell , N.M. Kolar , Amira Kassis , L.G. Karagounis , Louise M. Burke , John A. Hawley , Stuart M. Phillips
AIM
– Examine how dietary protein distribution affected muscle protein synthesis during:
(1) energy balance (EB)
(2) energy restriction (ER)
(3) ER plus resistance training (ER+RT)
DESIGN
– 4-wk ER diet was provided to overweight/obese older men (66 ± 4 y); n = 10/group
(a) Balanced BAL: 25% daily protein/meal x 4)
(b) Skewed pattern (SKEW: 7:17:72:4% daily protein/meal
– Myofibrillar and sarcoplasmic protein fractional synthetic rates (FSR) were measured after 2-wk ER, and after 2-wk ER+RT
CONCLUSIONS
(1) During ER a BAL consumption of protein stimulated synthesis of muscle contractile proteins more effectively than traditional, SKEW distribution
(2) Combining RT with a BAL protein distribution ‘rescued’ the lower rates of myofibrillar protein synthesis during moderate ER


INCREASED CONSUMPTION OF DAIRY FOODS AND PROTEIN DURING DIET AND EXERCISE INDUCED WEIGHT LOSS PROMOTES FAT MASS LOSS AND LEAN MASS GAIN IN OVERWEIGHT AND OBESE PRE-MENOPAUSAL WOMEN – 2011


Josse AR1, Atkinson SA, Tarnopolsky MA, Phillips SM.
AIM
– Determine how daily exercise (resistance and/or aerobic) and a hypoenergetic diet varying in protein and calcium content from dairy foods would affect the composition of weight lost in otherwise healthy, premenopausal, overweight, and obese women
METHODS
– 90 participants were randomized to 3 groups (n = 30/group)
(1) high protein, high dairy (HPHD) total dietary protein and dairy food-source protein consumed: 30 and 15%
(2) adequate protein, medium dairy (APMD) total dietary protein and dairy food-source protein consumed: 15 and 7.5%
(3) adequate protein, low dairy (APLD) total dietary protein and dairy food-source protein consumed: 15 and <2% of energy
RESULTS
(1) All groups lost body weight and fat
(2) however, fat loss during wk 8-16 was greater in the HPHD group than in the APMD and APLD groups
(3) HPHD group gained lean tissue with greater increase during 8-16 wk than APMD group, which maintained lean mass and APLD group, which lost lean mass
(4) HPHD group also lost more VAT as assessed by MRI and trunk fat as assessed by DXA than the APLD group
(5) The reduction in VAT in all groups was correlated with intakes of calcium and protein
CONCLUSION
– Diet- and exercise-induced weight loss with higher protein and increased dairy product intakes promotes more favorable body composition changes in women characterized by greater total and visceral fat loss and lean mass gain


 

 

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