Hops Extract Cuts Calorie Intake in Men

clinical-trial PMID: 35102364

Hops Extract Cuts Calorie Intake in Men

Quick Summary: A clinical trial tested hops extract, a natural compound from the plant used in beer, on healthy-weight men. Taking 500 mg of hops reduced how much they ate at lunch and snacks by about 17%, thanks to changes in hunger and fullness hormones. It shows promise for natural appetite control, but caused some stomach upset.

What the Research Found

This study explored how hops extract affects eating habits and gut hormones. Hops contain bitter compounds that interact with taste receptors in the gut, acting like a natural "brake" on overeating. Researchers measured calorie intake, hormone levels, and feelings of hunger or discomfort.

Key results include:
- Lower calorie intake: Men ate about 900 fewer kilojoules (roughly 217 calories) at meals after taking hops, compared to a fake pill (placebo). This happened whether the hops released in the stomach or lower in the intestines.
- Hormone changes: Hops boosted ghrelin (a hunger hormone) before meals but ramped up fullness hormones like cholecystokinin (CCK), glucagon-like peptide 1 (GLP-1), and peptide YY (PYY) after eating. It also lowered insulin and other blood sugar-related hormones without changing blood sugar levels.
- No change in appetite feelings: Men didn't report feeling less hungry overall, but they naturally ate less.
- Side effects: It caused mild stomach issues like nausea or bloating, especially with the stomach-release version. No effects on mood, energy, or food enjoyment.

These findings suggest hops could help control energy intake by tweaking gut signals, not by making you feel full right away.

Study Details

Who was studied: 19 healthy-weight men, all in good health with normal body weight (no obesity or other issues).
How long: A short-term trial where each man tried three options over separate days, with a 1-week break between each to clear effects.
What they took: A single 500 mg dose of hops extract in capsules. One type released quickly in the stomach (taken at 11:30 a.m.), another delayed until the intestines (taken at 11:00 a.m.). They compared it to an inactive placebo. Doses were given 1-1.5 hours before lunch, and eating was measured at lunch (noon) and an afternoon snack (2 p.m.), plus blood tests for hormones.

The setup was randomized and double-blind, meaning neither participants nor researchers knew who got the real hops until the end, for fair results.

What This Means For You

If you're a healthy-weight guy looking for natural ways to eat less without dieting, hops extract might help by quietly signaling your gut to curb calories—saving about 200-220 calories per meal in this study. It's like a built-in fullness boost from satiety hormones like GLP-1, which is even used in weight-loss drugs. You could try hops supplements (aim for delayed-release to avoid tummy trouble), but start low and chat with a doctor, especially if you have gut issues. For women or those with extra weight, results might differ—more research is needed. Overall, it's a cool, plant-based option for mindful eating, but not a magic fix for weight loss.

Study Limitations

This research has some caveats to keep in mind:
- Small and specific group: Only 19 healthy men were tested—no women, no one overweight, so it might not apply to everyone.
- One-time effects only: It looked at immediate results from a single dose, not long-term use or daily habits.
- Stomach side effects: The quick-release version caused more nausea and bloating, which could make it hard to stick with.
- Unclear links: We don't fully know how the bitter hops trigger these hormone shifts, and lower doses weren't tested.

More studies on diverse groups and safer formulas could make hops a stronger tool for appetite control. Always consult a healthcare pro before trying supplements.

Key Findings

The study found that both gastric (quick-release) and duodenal (delayed-release) administration of a 500 mg hop extract significantly reduced total ad libitum energy intake (EI) in healthy-weight men compared to placebo. Hop extract also stimulated prelunch ghrelin secretion and postprandial release of satiety hormones (cholecystokinin, glucagon-like peptide-1, peptide YY) while dampening postprandial insulin, glucose-dependent insulinotropic peptide, and pancreatic polypeptide responses. However, it caused mild-to-moderate gastrointestinal (GI) discomfort, particularly in the gastric treatment group.

Study Design

This was a randomized, double-blind, crossover clinical trial involving 19 healthy-weight men. Participants received three treatments—placebo, 500 mg hop extract in quick-release capsules (gastric delivery at 11:30 h), or 500 mg in delayed-release capsules (duodenal delivery at 11:00 h)—with a 1-week washout between interventions. Outcomes included acute EI at lunch (12:00 h) and afternoon snack (14:00 h), hormone levels (ghrelin, CCK, GLP-1, PYY, insulin, GIP, PP), and subjective measures (appetite, GI discomfort, mood).

Dosage & Administration

A single dose of 500 mg hop extract was administered either as quick-release capsules (targeting gastric delivery at 11:30 h) or delayed-release capsules (targeting duodenal delivery at 11:00 h). Placebo capsules were inert. Treatments were taken 1–1.5 hours before meals, with blood samples and appetite assessments conducted throughout the day.

Results & Efficacy

Energy Intake:
Gastric hop: 4473 kJ (95% CI: 3811–5134; P = 0.006).
Duodenal hop: 4439 kJ (95% CI: 3777–5102; P = 0.004).
Placebo: 5383 kJ (95% CI: 4722–6045).
Both hop treatments reduced EI by ~910–944 kJ (~17% decrease).
Hormonal Effects:
Increased prelunch ghrelin (P < 0.05) and postprandial CCK, GLP-1, and PYY (P < 0.05–0.01).
Decreased postprandial insulin, GIP, and PP (P < 0.05–0.01) without altering glycemia.
GI Discomfort:
Gastric hop caused more frequent mild-to-severe GI symptoms (e.g., nausea, bloating) than duodenal hop.

Limitations

Sample Size & Demographics: Small sample (n=19) limited to healthy-weight men; results may not generalize to women, overweight populations, or long-term use.
Short-Term Design: Measured acute effects only; sustainability of EI reduction and hormone modulation unknown.
Adverse Effects: Gastric delivery caused significant GI discomfort, potentially limiting practical applicability.
Mechanistic Gaps: Unclear how bitter receptor activation directly links to hormonal changes. Further research needed on lower doses or alternative formulations to minimize side effects.

Clinical Relevance

The hop extract demonstrates potential as a natural appetite regulator by modulating gut hormones (e.g., enhancing satiety signals like GLP-1/PYY and suppressing insulin spikes). For healthy-weight men, this could support strategies to reduce caloric consumption without affecting blood glucose. However, GI discomfort—particularly with gastric delivery—may hinder tolerability. Delayed-release formulations appear equally effective with fewer severe side effects, suggesting they could be preferable for supplementation. Users should weigh the benefits of reduced EI (~900 kJ saved per day) against potential GI distress. Future studies in diverse populations and with chronic dosing are required to validate these findings.