Which natural plants help reduce appetite?
There is clinical evidence that several plants can help reduce appetite:
- Saffron (Crocus sativus): Its safranal and crocin compounds increase the availability of serotonin in the brain. Randomized controlled trials (100 mg of extract twice daily) show a significant reduction in snacking and emotional cravings after 8 weeks. It is the best-documented plant for treating emotional cravings.
- Garcinia cambogia (hydroxycitric acid, HCA): inhibits ATP-citrate lyase, an enzyme that converts acetyl-CoA into fatty acids, modestly reducing appetite in the short term.
- Konjac (glucomannan): a soluble fiber for which the EFSA health claim regarding its contribution to weight loss is validated at a dose of 3 g/day taken with water before meals.
- Capsaicin (chili pepper): activates TRPV1 receptors, increases norepinephrine, and temporarily reduces appetite. The effect is diminished in regular consumers due to tolerance.
Do caffeine and green tea reduce appetite?
Caffeine is the best-documented stimulant appetite suppressant: as an adenosine receptor antagonist, it reduces plasma ghrelin by 15 to 25% within 30 to 60 minutes after ingestion. Green tea amplifies this effect: the EGCG + theine synergy inhibits COMT, prolonging the action of norepinephrine on hypothalamic neurons and adipocytes. This appetite-suppressing effect lasts 2 to 3 hours and is more pronounced in people who do not regularly consume caffeine. Take 20 to 30 minutes before a meal for optimal effectiveness.
Does intermittent fasting help reduce appetite?
Counterintuitively, intermittent fasting (IF) reduces appetite in the long term:
- Ghrelin adaptation: After 4 to 8 weeks of regular practice, ghrelin spikes become less pronounced and shift to coincide with the eating window.
- Improved leptin sensitivity: time-restricted eating reduces metabolic inflammation and restores satiety signals.
- Stabilization of blood glucose levels: Long periods without carbohydrate intake reduce the blood glucose spikes and crashes that trigger cravings.
Contraindications: pregnancy, breastfeeding, eating disorders, diabetes treated with insulin or sulfonylureas.
What is emotional eating, and how can it be reduced?
Emotional eating is the consumption of food in response to emotions rather than physiological hunger. The neuroscience behind it:
- Stress-induced cortisol stimulates dopaminergic reward circuits, generating cravings for palatable foods.
- A drop in serotonin (depression, fall, premenstrual syndrome) triggers carbohydrate cravings via the tryptophan-insulin-serotonin loop.
- Activation of the endocannabinoid system (stress, lack of sleep) amplifies the pleasure derived from comfort foods.
Tryptophan can reduce emotional cravings by supporting serotonin levels. Cardiac coherence and mindfulness meditation reduce cortisol and gradually decouple emotions from the eating response.
Is sleep essential for reducing appetite?
Quality sleep is probably the most underrated strategy for reducing appetite:
- 7 to 9 hours normalize ghrelin and leptin levels within 2 to 3 nights.
- Deep sleep maximizes growth hormone secretion, which preserves muscle mass and reduces appetite the next day.
- Untreated sleep apnea: Affected individuals have ghrelin levels 30 to 40% higher than healthy subjects. CPAP treatment normalizes these levels within a few weeks.
Do fiber and protein reduce appetite in the long term?
Soluble fiber and protein are the best-documented nutritional appetite suppressants:
- Protein stimulates GLP-1 and PYY (satiety hormones) for 3 to 4 hours by stimulating intestinal L cells.
- Soluble fiber slows gastric emptying and prolongs mechanical satiety by an additional 1 to 2 hours.
- Together: a meal rich in protein and fiber reduces calorie intake at the next meal by 15 to 20 percent, according to intervention studies.
