How to increase your BMR, what actually works
There is a lot of bad advice on boosting metabolism, superfoods, cold showers, eating every two hours. Most of it is noise. Here is what the research actually shows about raising your basal metabolic rate, and what is a myth.
The only reliable way to permanently increase your BMR is to build muscle through resistance training. Muscle burns roughly three times more calories at rest than fat. Everything else, eating frequency, metabolism-boosting foods, cold exposure, has a negligible or temporary effect on resting metabolic rate.
What works and what doesn't, summary
1. Resistance training, the only permanent fix
This is not debated in the research. Building muscle is the only reliable method for permanently increasing resting metabolic rate. Muscle tissue is metabolically expensive. It burns roughly 13 kcal per kg per day at rest, compared to approximately 4.5 kcal per kg for fat tissue.
The practical implication: adding 5kg of muscle raises your BMR by roughly 42–65 kcal/day. This sounds modest, and it is, in isolation. But it represents a permanent upward shift in your resting burn that compounds over years. A person who builds and maintains 10kg more muscle than a sedentary peer of the same age burns roughly 100 kcal more per day at rest for life. That is a 36,500 kcal annual difference.
Two to three sessions per week of progressive resistance training is sufficient. "Progressive" is key, the stimulus for muscle growth requires gradually increasing the challenge over time. Use the body fat calculator to track your lean mass over months to confirm muscle gain is actually happening.
2. Eat enough protein
Protein has the highest thermic effect of the three macronutrients, your body burns roughly 20–30% of protein calories just through digestion and processing, compared to 5–10% for carbohydrates and 0–3% for fat. This contributes a modest daily calorie burn from dietary protein alone.
More importantly, adequate protein intake, 1.6–2.2g per kg of bodyweight, is essential for building and preserving the muscle mass that drives BMR. Without sufficient protein, resistance training produces far less muscle growth, undermining the primary BMR-raising strategy. See our guide to hitting your protein target for practical strategies.
3. Do not crash diet
This is the most overlooked aspect of BMR management, not raising it, but avoiding suppressing it. Severe calorie restriction (eating significantly below TDEE for extended periods) triggers metabolic adaptation, where the body reduces BMR by 10–15% as a survival response.
This is why people who repeatedly crash diet find it progressively harder to lose weight. Each cycle of severe restriction reduces BMR further. The adapted metabolic rate partially recovers when normal eating resumes, but research suggests some suppression persists long-term in habitual crash dieters.
The solution is to maintain a moderate deficit of 300–500 kcal below TDEE, large enough to produce fat loss, small enough to avoid triggering significant metabolic adaptation. The calorie deficit calculator shows you exactly how long a moderate deficit takes to reach your goal, which removes the temptation to go more aggressive.
4. Prioritise sleep
Poor sleep does not directly lower BMR in a measurable way, but it suppresses it indirectly through multiple mechanisms. Sleep deprivation increases cortisol, which promotes muscle breakdown. It reduces growth hormone secretion, which is critical for muscle repair and synthesis. It elevates ghrelin and suppresses leptin, creating increased appetite that undermines calorie control.
Consistently sleeping less than 7 hours per night creates conditions that actively work against building the muscle mass that would otherwise raise BMR. It is not a metabolism-boosting intervention. It is a damage-prevention one.
What does not work, the myths
Eating every 2–3 hours
The idea that frequent small meals "stoke your metabolic fire" has been thoroughly debunked. The thermic effect of food is determined by total daily intake, specifically total protein and total calories, not how that intake is distributed across meals. Eating six small meals produces the same thermic effect as eating three larger ones with the same total food. Meal frequency has no meaningful impact on BMR.
Green tea, caffeine, and "metabolism-boosting" supplements
Caffeine does increase metabolic rate, by approximately 3–11% for a few hours after consumption, primarily through thermogenesis and increased nervous system activity. This is a real but temporary effect that does not persist as tolerance develops. The boost is too small and too transient to meaningfully affect BMR. Green tea extracts containing EGCG show similar modest, temporary effects in some studies.
The supplement industry markets these effects aggressively. The honest summary: They may add 50–100 kcal to your daily burn temporarily, they do not raise your resting BMR, and tolerance reduces even this effect over time.
Cardio exercise
Cardio burns calories during exercise and elevates metabolic rate for a period afterwards through EPOC (excess post-exercise oxygen consumption). But it does not raise resting BMR long-term. High volumes of endurance training with inadequate calorie intake can actually reduce muscle mass and therefore lower BMR over time.
Cardio is valuable for cardiovascular health, TDEE (your total activity-adjusted calorie burn), and general fitness. It should not be confused with raising your basal metabolic rate.
Cold exposure
Cold showers and ice baths produce brown adipose tissue (BAT) activation, which does generate heat and burn calories. The effect exists but is small, estimates range from 50–300 kcal during extreme cold exposure. Regular cold exposure does not permanently increase BMR. It is not a practical metabolism-raising tool.
How to track whether your BMR is changing
The most practical way to assess whether your BMR is genuinely increasing is to recalculate it regularly using the BMR calculator as your weight and body composition change. If you are building muscle while maintaining or losing weight, your BMR will increase even if your total weight stays similar, because muscle replaces fat at the same bodyweight but burns more calories.
| Body composition | BMR estimate | Daily difference |
|---|---|---|
| 25% body fat (20kg fat) | ~1,794 kcal | Baseline |
| 20% body fat (16kg fat, +4kg muscle) | ~1,832 kcal | +38 kcal |
| 15% body fat (12kg fat, +8kg muscle) | ~1,871 kcal | +77 kcal |
These gains are modest but genuine and permanent. Unlike the temporary effects of supplements or dietary changes, Over a year, an extra 77 kcal/day adds up to 28,000 kcal, roughly 3.6kg of fat that does not need to be actively restricted.