Research

Hormonal

Plasma ghrelin levels increase with fasting and decrease after meals, with levels being higher after diet-induced weight loss compared to gastric bypass surgery.

When you lose weight through dieting, your body naturally increases ghrelin levels, making you hungrier. This is a biological response, not a personal failure. Gastric bypass surgery, by contrast, suppresses ghrelin levels, which may contribute to its effectiveness. Managing expectations about increased hunger during weight loss can help in adhering to long-term strategies.

StrongSupportsVERY_HIGH confidence
Rat serum ghrelin concentrations were increased by fasting and were reduced by refeeding or oral glucose administration... They found an increase in the plasma ghrelin level with diet-induced weight loss. Gastric bypass was associated with markedly suppressed ghrelin levels, possibly contributing to the weight-reducing effect of the procedure.
Mercedes Gil‐Campos et al. · British Journal Of Nutrition · 2006

Why this rating

Supported by multiple studies (Tschop, Cummings) cited in the review.

Source

Ghrelin: a hormone regulating food intake and energy homeostasis

Mercedes Gil‐Campos et al. · British Journal Of Nutrition · 2006

DOI 10.1079/bjn20061787

narrative_reviewCited 217×
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DOI resolved against Crossref · corpus check 2026-06-10

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