People With Spinal Cord Injury Feel Fuller Faster Despite Similar GLP-1 and PYY Levels | Research

The takeaway

Spinal cord injury patients showed enhanced early postprandial satiety and ate 37% less at ad libitum meals than able-bodied controls, despite no significant differences in GLP-1, PYY, or ghrelin levels.

37% less intake
SCI patients voluntarily ate 37% less at ad libitum meals despite normal levels of appetite-regulating peptides GLP-1, PYY, and ghrelin

What the researchers found

SCI patients showed higher early postprandial fullness (d=0.83) and satisfaction (d=0.87), ate less at ad libitum meals (1,086 vs 1,713 kJ, d=1.00, p=0.020), but had no significant differences in GLP-1, PYY, or acylated ghrelin responses.

Why it matters

Obesity in SCI patients was assumed to partly involve impaired appetite regulation. This study shows appetite is actually enhanced, meaning obesity in SCI is driven primarily by reduced energy expenditure, not overeating — which changes how weight management should be approached.

The numbers in context

12+12; fullness d=0.83; satisfaction d=0.87 (0-60 min); ad lib intake 1,086 vs 1,713 kJ (p=0.020); no hormone differences (PYY, GLP-1, ghrelin)

How the study worked

Counterbalanced crossover study. 12 men with high-level SCI (≥T6) and 12 able-bodied controls consumed covert high-energy (2,513 kJ) and low-energy (1,008 kJ) preloads. Subjective appetite and ad libitum intake measured. Appetite hormones measured in high-energy trial.

Who was studied

Men with high-level spinal cord injury (≥T6) and able-bodied controls

What this study cannot tell us

Small study (24 participants). Only men studied. High-level SCI (≥T6) only — results may differ for lower-level injuries. Single center. Appetite hormone measurements may not capture all relevant signals.

How to read the evidence

Moderate evidence: well-designed counterbalanced crossover study with large effect sizes, but small sample (24 total, men only).

When this study was published

Published 2021. Research on appetite regulation in SCI populations remains limited.

The bigger picture

This study adds to our understanding of how GLP-1 and other satiety hormones interact with the nervous system. The dissociation between normal hormone levels and enhanced satiety in SCI suggests that gut-brain signaling pathways beyond these peptides are important for appetite regulation.

Questions still open

What mechanisms drive the enhanced satiety in SCI if GLP-1, PYY, and ghrelin are unchanged?
Does the enhanced satiety persist long-term or does it diminish over time?
Should weight management in SCI focus entirely on energy expenditure rather than appetite control?

Common questions

Why do people with spinal cord injuries gain weight if they feel fuller?

SCI patients gain weight primarily because they burn far fewer calories due to reduced muscle mass and inability to exercise — not because they eat too much. This study shows they actually eat less than able-bodied people after identical meals.

Are appetite hormones like GLP-1 affected by spinal cord injury?

This study found GLP-1, PYY, and ghrelin levels were similar between SCI patients and controls. The enhanced satiety appears to come from other mechanisms, possibly altered gut signaling or autonomic changes from the injury itself.

Read the original research

Accentuated early postprandial satiety in people with spinal cord injury versus able-bodied controls.

Appetite, 167, 105628

View on PubMed ↗Publisher’s paper ↗

Citation

Fenton, Jordan M; King, James A; Hoekstra, Sven P; Willis, Scott A; Ogawa, Takahiro; Goosey-Tolfrey, Victoria L. (2021). Accentuated early postprandial satiety in people with spinal cord injury versus able-bodied controls.. Appetite, 167, 105628. https://doi.org/10.1016/j.appet.2021.105628