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A High-Fat/High-Sugar Diet Is Associated with Reduced Motor Unit Number and Neuromuscular Dysfunction in
Carlos J Padilla1,2, Samuel R Hodge3, Wiliam Carvajal4
1Department of Kinesiology, University of Wisconsin-Madison, Madison, WI 53706, USA.
Life (Basel, Switzerland)
|June 26, 2026
Summary
A high-fat, high-sugar diet (HFHSD) accelerated neuromuscular decline in aging rats, reducing motor unit numbers and muscle function. This suggests obesogenic diets may worsen age-related motor system impairments.
Area of Science:
- Aging Research
- Neuroscience
- Metabolic Health
Background:
- Aging is linked to metabolic dysfunction and neuromuscular decline.
- Obesogenic diets may worsen these age-related processes.
- The impact of high-fat, high-sugar diets (HFHSD) on aging neuromuscular systems is not well understood.
Purpose of the Study:
- To investigate the effects of HFHSD on neuromuscular integrity in late-middle-aged female rats.
- To determine if HFHSD accelerates age-associated neuromuscular decline.
Main Methods:
- Late-middle-aged female F344 rats were fed either HFHSD or regular chow for 10 weeks.
- Longitudinal assessments included body composition, motor unit number estimation (MUNE), grip strength, and muscle contractile torque.
- Electrical impedance myography (EIM) was used post-intervention.
Main Results:
- HFHSD significantly increased body mass and adiposity.
- HFHSD rats showed reduced hindlimb MUNE and impaired muscle contractile torque.
- HFHSD was associated with elevated resistance in EIM, suggesting altered tissue properties.
Conclusions:
- Initiating HFHSD in late middle age may accelerate neuromuscular decline before typical age-related motor unit loss.
- HFHSD exposure is linked to reduced motor unit numbers and muscle function impairments.
- Diet-induced metabolic dysfunction may contribute to early neuromuscular impairment during aging.
