Author(s): LOWISZ, C., JANSSEN, T., LEES, M., MCKENDRY, J., LIM, C., LYONS, S., ALIZADEH, A., PHILLIPS, S., Institution: MCMASTER UNIVERSITY, Country: CANADA, Abstract-ID: 1129

INTRODUCTION:
Aging and obesity frequently coexist and, when combined with sarcopenia, are major risk factors for the development of type 2 diabetes mellitus (T2DM). Resistance exercise training (RET) increases muscle mass, but traditional heavy-load RET can be impractical for older adults. Lighter-load RET offers a safer, more accessible alternative, which when combined with sufficient protein intake supports exercise-induced muscle gains. While high-quality proteins such as whey enhance muscle responses to exercise, the role of protein quality to support muscle adaptation in older adults with overweight/obesity is unknown. We examined the effects of lighter-load RET combined with twice-daily protein supplementation with whey (WHEY) or collagen (COLL) on body composition and glycemic control in older adults with overweight/obesity. We hypothesized that RET would improve body composition and glycemic control, with WHEY providing greater benefits than COLL.
METHODS:
Sixty-seven older (68 +/- 5 y; BMI 29.8 +/- 3.9 kg/m2) males and females participated in a 12-week lighter-load RET program (3 sessions/week) with twice daily 25g WHEY (n=35) or COLL (n=32). Body composition was assessed by DXA, and glycemic control was assessed by oral glucose tolerance tests (OGTT).
RESULTS:
Significant group-by-time interactions were observed for lean mass, body fat percentage, and fat mass (p<0.05). Lean mass increased in WHEY (1.3 +/- 1.2 kg; p<0.0001), but to a lesser extent in COLL (0.2 +/- 1.2 kg; p=0.013). Body fat percentage decreased significantly in WHEY (-1.2 +/- 1.3%; p<0.0001), but not in COLL (-0.5 +/- 1.1%; p=0.095). Fat mass decreased significantly in WHEY (-0.9 +/- 1.4 kg; p<0.0001), but not in COL (-0.7 +/- 1.3 kg; p=0.14). We observed a main effect of time for both visceral fat mass (-104 +/- 209 g; p<0.001) and fasting glucose (-0.14 +/- 0.50 mmol/L; p=0.025).
CONCLUSION:
Lighter-load RET combined with protein supplementation increased lean mass, decreased visceral fat, and improved glycemic regulation in older adults with overweight/obesity. Higher quality protein supplements, WHEY, were more effective for enhancing lean mass gains and supporting fat loss during lighter-load RET, ultimately enhancing body composition. Glycemic regulation improved with RET regardless of protein supplement.