Most “metabolism” and “fat burner” products overpromise. This is an editor’s shortlist of the few ingredients with reasonable evidence — as modest helpers alongside diet, movement and sleep, not shortcuts. It is not a lab test or medical advice.
Quick comparison
| Ingredient | Best for | Typical daily amount | What to look for |
|---|---|---|---|
| Soluble fiber (psyllium) | Fullness, appetite control | 3–10 g | Start low; plenty of water |
| Protein powder | Preserving muscle, satiety | 20–30 g per serving | Simple ingredients; low added sugar |
| Green tea extract | A small energy nudge | Per label | Caffeine content; avoid mega-doses |
Our picks
Soluble Fiber Supplement (e.g. psyllium — Metamucil, NOW Psyllium Husk)
- Psyllium slows digestion and supports fullness between meals
- Start with 3–5 g and plenty of water, then build up
- Cheap, well studied, and easy to add to a routine
Inexpensive · widely available
Check Price →Protein Powder (e.g. Optimum Nutrition, Naked)
- Protein helps preserve muscle and keeps you full
- 20–30 g per serving is a common, useful amount
- Choose simple ingredients and low added sugar (whey or plant-based)
Widely available
Check Price →Green Tea Extract (e.g. NOW, Nature's Bounty)
- May give a small, temporary bump in energy expenditure
- The effect is modest — it is not a fat burner
- Mind the caffeine, and avoid very high-dose extracts
Inexpensive
Check Price →How to choose
Think of these as small helpers, not solutions. Fiber and protein are the most useful for most people because they work on appetite and muscle — the things that actually make a calorie balance easier to sustain. Green tea extract is optional and its effect is minor. If a product promises dramatic weight loss on its own, treat that as a red flag. The National Center for Complementary and Integrative Health has a balanced overview of green tea.
New to this? Start with our explainer on fiber for weight management.