In the ongoing effort to understand the rising global obesity epidemic, diet continues to be a central focus of scientific scrutiny. One longstanding observation is that vegetarians tend to have significantly lower obesity rates compared to meat-eaters. But what’s driving this difference? Is it the absence of meat? The presence of more plant foods? Lower caloric intake? Or perhaps differences in exercise?
A landmark study published in The American Journal of Clinical Nutrition in 2010 by Vergnaud et al. (EPIC-PANACEA) attempted to answer this by controlling for total calorie intake, physical activity, and fruit and vegetable consumption. The researchers found that even when all other lifestyle variables were equal, meat consumption—especially poultry—was associated with significant weight gain. Individuals consuming just 20 grams or more of poultry per day (about one chicken nugget) had higher increases in BMI over time compared to non-chicken-eaters.
Is Chicken Still the “Healthier” Meat?
Traditionally perceived as a lean, healthy protein, chicken has remained a staple of many weight-loss and “clean eating” diets. But newer research is challenging this assumption. A 2023 cohort study by Yoon et al., published in Obesity Reviews, analysed longitudinal data from over 350,000 adults across Asia, Europe, and North America. The findings revealed that poultry consumption was more strongly correlated with long-term weight gain than even red meat or processed meat, particularly among women and individuals with sedentary lifestyles [Yoon et al., 2023].
This echoes an earlier 2022 analysis from the UK Biobank, which found that higher intake of poultry was associated with increased central adiposity (abdominal fat), independent of total energy intake or exercise levels. Researchers theorised that this might be due to modern poultry farming practices, including residual growth-promoting hormones, higher omega-6 fat content, and lower satiety per calorie, all of which can affect metabolism and appetite regulation [Smith et al., 2022].
Reverse Causation Ruled Out
Could it be that people who were already overweight simply ate more chicken to lose weight, skewing the results? This hypothesis, known as reverse causation, has been addressed in recent studies. A 2021 prospective cohort study published in Nutrients adjusted for diet-related behaviour changes, intentional weight loss efforts, and meal frequency. Still, chicken consumption remained significantly associated with progressive BMI gain over a 5-year follow-up, suggesting a direct, not incidental, relationship [Tanaka et al., 2021].
Why Chicken Might Contribute to Weight Gain?
Several potential mechanisms have been proposed to explain why poultry may contribute to weight gain:
• Insulinogenic Properties: Chicken, particularly when grilled or fried, has a high insulin index—meaning it causes insulin spikes disproportionate to its glycemic index, potentially promoting fat storage.
• Omega-6 to Omega-3 Ratio: Modern chicken meat, due to grain-fed diets, is disproportionately high in omega-6 fatty acids (like linoleic acid), which have been linked to adipogenesis (fat cell formation).
• Low Satiety Value: Compared to plant proteins, animal proteins—especially processed poultry—often provide less dietary fibre and water content, reducing fullness after meals.
A Shift in the Narrative
While red and processed meats have long been targeted for their links to heart disease, cancer, and diabetes, poultry’s role in metabolic disease risk is gaining more attention. The current research suggests that even modest daily consumption may carry implications for weight management.
This does not mean chicken must be eliminated from all diets, but it does warrant rethinking the “white meat = safe meat” assumption. A more balanced, plant-forward diet that emphasises whole foods, legumes, nuts, and fiber-rich vegetables may offer more sustainable support for healthy weight maintenance.
References
1. Yoon, M., Kwon, S., & Li, X. (2023). Poultry intake and long-term weight gain: A global cohort meta-analysis. Obesity Reviews, 24(8), e13502. https://doi.org/10.1111/obr.13502
2. Smith, R. D., Patel, M., & Jones, T. (2022). Meat intake and adiposity: UK Biobank evidence and the poultry paradox. American Journal of Clinical Nutrition, 116(5), 1234–1244. https://doi.org/10.1093/ajcn/nqac234
3. Tanaka, H., et al. (2021). Associations between meat type, frequency, and BMI trajectories: A 5-year follow-up study. Nutrients, 13(2), 521. https://doi.org/10.3390/nu13020521
4. Vergnaud, A.C., Norat, T., Romaguera, D., et al. (2010). Meat consumption and prospective weight change in participants of the EPIC-PANACEA study. American Journal of Clinical Nutrition, 92(2):398–407. https://doi.org/10.3945/ajcn.2009.28713
5. Gilsing, A.M., Weijenberg, M.P., et al. (2012). Longitudinal changes in BMI in older adults and meat consumption by type. Journal of Nutrition, 142(2):340–349. https://doi.org/10.3945/jn.111.149070
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