In short, yes. A new study published in the Physiological Society has unraveled that moderate aerobic exercise can temporarily suppress appetite in individuals with obesity.

Why is This Study Important?

1. The study employs a crossover design. This strengthens internal validity by ensuring that participants serve as their controls, reducing variability due to individual differences.
2. The use of multiple biomarkers (IL-6, IL-7, irisin, NPY, leptin) provides a multi-faceted view of appetite regulation rather than relying on a single hormone.
3. Findings on IL-6 elevation post-exercise are consistent with prior research (Bornath et al., 2023; Andarianto et al., 2022), adding credibility to the results.

Limitations of the study

1. The study included only 11 participants, limiting statistical power and generalizability to broader populations.
2. The sample consisted only of males with obesity, meaning the results may not apply to females or individuals with different BMI categories or fitness levels.
3. The study found no significant change in IL-7 levels post-exercise, yet this contrasts with animal studies showing that IL-7 reduces appetite (Macia et al., 2010).
4. The authors speculate that the exercise intensity may not have been high enough to alter IL-7 levels, indicating a need for more diverse exercise protocols.
5. The study used bioelectrical impedance analysis (BIA) to measure body fat, whereas DEXA (dual-energy X-ray absorptiometry) is more accurate for assessing visceral and ectopic fat.
6. The study only measured short-term effects (immediate and 1-hour post-exercise), meaning it does not capture longer-term appetite regulation mechanisms.
7. Appetite regulation is influenced by habitual exercise patterns, not just a single session, so future studies should consider longitudinal designs.
8. The study does not account for psychological factors (e.g., stress, mood, food cravings), which may influence appetite perception independent of hormonal changes.
   

Delving into the study

Understanding how moderate aerobic exercise influences appetite regulation and the hormones or cytokines involved is critical for designing effective weight management strategies in individuals with obesity.

The present study provides valuable insights into these mechanisms by examining changes in interleukin 6 (IL-6), irisin, neuropeptide Y (NPY), interleukin 7 (IL-7), and leptin following 60 minutes of moderate-intensity continuous exercise (MICE).

The results indicate that IL-6 and irisin concentrations rise while NPY decreases and subjective appetite is suppressed. However, IL-7 and leptin levels do not show significant changes.

IL-6

IL-6 (interleukin 6) is a signaling protein that increases during exercise and can affect metabolism, appetite, and recovery.

One of the most noteworthy findings is the increase in IL-6 observed immediately post-exercise, which remained elevated an hour later.

This aligns with previous work showing that IL-6 is a cytokine released predominantly by skeletal muscle during and after exercise, particularly when slow-twitch fibers are recruited and glycogen stores are depleted.

The current study’s results reinforce the hypothesis that IL-6 may contribute to the phenomenon often termed “exercise-induced anorexia.”

While the precise mechanism through which IL-6 might suppress appetite is still under investigation, there is evidence it can cross the blood–brain barrier and influence appetite-related pathways in the hypothalamus.

Indeed, studies have demonstrated that a substantially higher dose of IL-6 can reduce food intake, highlighting its potential role in acute appetite suppression.

IL-7

An equally intriguing aspect is the lack of significant changes in IL-7.

Although animal research suggests IL-7 may reduce food intake by affecting pro-opiomelanocortin (POMC) neurons (neurons in the brain that suppress hunger), the current findings show that moderate-intensity exercise in obese males does not induce a measurable change in IL-7 levels.

It is possible that the exercise intensity or duration was insufficient to trigger an increase in IL-7, or that IL-7 is more responsive to different forms of exercise, such as intermittent or higher-intensity activities.

Given that prior research indicates individuals with obesity might already exhibit elevated IL-7, it may also be that a ceiling effect exists, preventing further increases under these conditions.

Irisin

Irisin is a hormone released during exercise that helps regulate metabolism and may play a role in appetite suppression and fat conversion.

The increase in irisin—approximately 20% higher post-exercise—offers another piece in the puzzle of exercise-mediated appetite regulation. Studies show that irisin may reduce food intake when administered centrally.

The current findings thus reinforce the possibility that irisin contributes to short-term appetite suppression induced by exercise.

Leptin

Turning to leptin, the study reports no significant changes in leptin concentration following 60 minutes of moderate aerobic exercise, aligning with some prior findings but contradicting others that have shown reductions.

Several factors, including fasting status, baseline leptin levels, and exercise duration, may explain these discrepancies.

Moreover, leptin’s role in appetite regulation is both acute and chronic, and a single session of exercise may not be sufficient to produce measurable shifts in circulating levels.

Still, leptin remains an important hormone to monitor, given its established role in signaling energy stores and modulating hypothalamic appetite pathways.

NPY

NPY, or neuropeptide Y,  is a neurotransmitter that stimulates appetite and regulates energy balance. It plays a key role in increasing food intake and reducing energy expenditure.

The decrease in NPY one hour post-exercise is important because NPY stimulates hunger.

While peripheral NPY does not readily cross the blood–brain barrier, it may still influence appetite via indirect pathways.

The current finding contrasts with a previous study of endurance athletes, suggesting exercise duration, intensity, and baseline fitness may modulate the NPY response.

Given that individuals with obesity often exhibit elevated plasma NPY, any exercise-induced decline could be particularly relevant for managing appetite and energy intake in this population.

Moderate exercise can reduce your appetite

Crucially, the study documents subjective appetite suppression following moderate-intensity exercise, a phenomenon supported by numerous investigations.

While the exact mechanisms remain only partially understood, the rise in IL-6 and irisin, together with the drop in NPY, likely work in concert to reduce hunger cues.

Exercise-related psychological factors—such as stress relief, mood elevation, and altered perceived exertion—may also contribute to this outcome.

Takeaway

Overall, this study enriches our understanding of how moderate aerobic exercise can transiently suppress appetite in individuals with obesity, implicating IL-6, irisin, and NPY as pivotal mediators.

While not all appetite-related factors responded significantly, the findings underscore the multifaceted nature of exercise-induced hunger regulation.

Future research building on these insights may offer new strategies for harnessing exercise to promote healthy weight management and metabolic well-being.