What actually works — a quick summary
Quick read · 4 min
Here is what the clinical evidence actually shows, without opinions or rankings.
Average weight loss by approach (trial data)
Approximate figures from randomised controlled trials. Individual results vary. In clinical trials, participants lost these amounts — your results may differ.
If your goal is a specific percentage of weight loss, the evidence can help you understand which approaches are most likely to achieve it.
TIER 1 — Highest average weight loss
Prescription medications
Strong evidenceHighest weight loss of any treatment category. Require a doctor and a prescription.
- •Weight loss in trials: 6–21% of body weight — that's 14–50 lbs for a 240 lb person
- •Require a prescription and ongoing treatment — weight tends to return if stopped
- •Cost: ~$149/month (daily pill) to ~$1,350/month (weekly injection) at list price
TIER 2 — Moderate weight loss
Diet changes
Strong evidenceWorks if sustained. The foundation of weight management alongside any other treatment.
- •A 500 kcal/day deficit produces roughly 0.5 kg (1 lb) per week
- •No single diet is clearly best — adherence is the main factor
- •High protein (1.2–1.6g/kg/day) helps preserve muscle during weight loss
Exercise
Moderate evidenceModest direct weight loss, but major health benefits. Essential for muscle preservation.
- •150+ minutes of aerobic exercise per week for meaningful fat loss
- •Exercise alone: approximately 1–2 kg loss over 6 months in trials
- •Resistance training is especially important on GLP-1 drugs — prevents muscle loss
TIER 3 — Supportive / Foundational
Supplements
Weak–moderate evidenceLimited evidence. Most produce less than 2 kg weight loss. Natural does not mean effective.
- •Most supplements: 1–2 kg average loss in trials — far less than prescription drugs
- •Best-evidenced options: orlistat OTC (Alli), berberine, spirulina
- •Some carry safety risks despite being sold without a prescription
After significant weight loss
Body contouring procedures
Moderate evidenceBody-shaping procedures after weight loss — not weight loss treatments themselves.
- •CoolSculpting, EMSculpt, radiofrequency: improve body shape, not scale weight
- •Loose skin procedures address a real concern after significant weight loss
- •Not substitutes for weight loss treatment
The most effective approach
Combining medication with dietary change and regular exercise consistently produces better results than any single approach alone. The right mix depends on your situation — talk to a doctor about what makes sense for you.
Next step most people take
Based on clinical trials · No rankings · Every claim linked to source
Last reviewed: April 2026