Your basal metabolic rate (BMR) accounts for roughly 60 to 75 percent of the calories you burn each day, just keeping your body alive. The most effective way to increase it is to build more muscle through strength training, but several other factors, from what you eat to how much water you drink, play a measurable role.
Why Muscle Mass Matters Most
Muscle tissue is far more metabolically active than fat. At rest, one pound of muscle burns roughly 4.5 to 7 calories per day, while fat tissue burns considerably less. That gap sounds small on a per-pound basis, but it scales quickly. Adding 10 pounds of muscle over a year of consistent training could raise your resting calorie burn by 45 to 70 calories per day, and the effect is permanent as long as you maintain that muscle.
Resistance training is the most reliable tool here. Lifting weights, using resistance bands, or doing bodyweight exercises like push-ups and squats all stimulate muscle growth. Two to four sessions per week, targeting major muscle groups, is enough to produce meaningful gains. The metabolic benefit comes not just from the muscle itself but also from the repair process: your body spends extra energy rebuilding muscle fibers for hours after a strength workout, a phenomenon sometimes called “afterburn.”
Eat More Protein
Your body uses energy to digest food, a process called the thermic effect of food. Not all nutrients cost the same amount of energy to process. Protein burns 20 to 30 percent of its own calories during digestion, compared to 5 to 10 percent for carbohydrates and less than 3 percent for fat. If you eat 400 calories of chicken breast, your body uses 80 to 120 of those calories just breaking it down and absorbing it.
Replacing some of the carbohydrates or fats in your diet with protein-rich foods, like eggs, fish, legumes, or lean meats, increases your total daily calorie burn without requiring you to eat less. Higher protein intake also supports muscle growth, reinforcing the most powerful metabolic lever you have. Most active adults benefit from consuming 0.7 to 1 gram of protein per pound of body weight per day.
Drink Enough Water
Drinking water temporarily speeds up your metabolism. A study published in The Journal of Clinical Endocrinology & Metabolism found that drinking 500 ml (about 17 ounces) of water increased metabolic rate by 30 percent. The effect kicked in within 10 minutes, peaked around 30 to 40 minutes, and lasted for more than an hour. The researchers attributed part of this to the energy your body spends heating the water to body temperature.
This doesn’t mean chugging water is a weight-loss strategy on its own, but staying consistently hydrated throughout the day keeps this small metabolic boost ticking along. If you’re mildly dehydrated, which many people are, your metabolism is running slightly below its potential.
Cold Exposure and Brown Fat
Your body burns extra calories when it needs to generate heat. Research published in The Journal of Clinical Investigation found that repeated cold exposure over 10 days increased a process called non-shivering thermogenesis, where the body produces heat without muscle contractions, from about 11 percent above resting levels to 18 percent. This was driven partly by an expansion of brown fat, a type of fat tissue that burns calories to generate warmth. Participants’ brown fat volume grew from an average of 665 cc to 913 cc after the cold acclimation period.
In practical terms, this could look like taking cold showers, spending time outdoors in cooler weather, or keeping your home slightly cooler. The calorie burn from cold exposure is modest, but it adds up over time, and brown fat activity appears to improve blood sugar regulation as a bonus.
Caffeine Provides a Small Boost
Caffeine increases resting energy expenditure by about 3 to 4 percent at doses as low as 100 mg, roughly one cup of coffee. The effect lasts a few hours and works by stimulating your nervous system to burn more energy at rest. For someone with a BMR of 1,500 calories per day, that translates to an extra 45 to 60 calories burned.
This is a real effect, but it’s small enough that it only matters as one piece of the puzzle. Your body also develops some tolerance to caffeine over time, which may blunt the metabolic boost slightly if you’re a daily coffee drinker.
Meal Frequency Does Not Matter Much
A popular claim suggests that eating six small meals a day “stokes your metabolism” compared to three larger meals. The evidence doesn’t support this. Intervention studies comparing frequent small meals to fewer larger ones consistently show no meaningful difference in 24-hour energy expenditure. One study conducted inside a metabolic chamber, where calorie burn was precisely measured, found no change in daily energy expenditure when participants switched from three meals to two. Your body processes the same total amount of food and spends roughly the same amount of energy digesting it, regardless of how you divide your meals.
Eat on whatever schedule keeps you satisfied and energized. If six small meals help you avoid overeating, that’s a valid reason to follow that pattern. Just don’t expect it to raise your BMR.
Your BMR Stays Stable Longer Than You Think
Many people assume their metabolism plummets steadily after age 30. A large-scale analysis covered by Harvard Health Publishing tells a different story. Basal metabolic rate stays remarkably stable from age 20 to about 60, regardless of sex. The decline begins around age 60, dropping at a rate of roughly 0.7 percent per year after that. The reason BMR appears to fall in middle age for many people is not aging itself but a gradual loss of muscle mass from reduced physical activity.
This is good news. It means the metabolic slowdown most people experience in their 30s, 40s, and 50s is largely within their control. Maintaining or building muscle through strength training can offset the loss that would otherwise drag your BMR down over the decades.
Thyroid Health Sets the Baseline
Your thyroid gland acts as the master thermostat for your metabolism. It produces a hormone that gets converted into its active form in your tissues, and this active form directly controls how fast your cells burn energy. When thyroid function is low (hypothyroidism), BMR drops noticeably, often by 15 to 40 percent. Symptoms include fatigue, weight gain, cold sensitivity, and sluggish digestion.
If you’ve been doing everything right, building muscle, eating well, staying active, and still feel like your metabolism is unusually slow, a simple blood test can check your thyroid function. An underactive thyroid is common, affecting roughly 5 percent of adults, and is treatable.
Putting It All Together
The strategies that move the needle most are strength training and adequate protein intake, because they directly increase the amount of metabolically active tissue on your body. Hydration, caffeine, and cold exposure each add a small but real boost. Meal timing and frequency are largely irrelevant to BMR. And the age-related decline most people worry about is primarily a muscle-loss problem, not an inevitable feature of getting older. Focus on building and keeping muscle, and the rest follows.