When people lose weight, their bodies adjust how many calories they burn, and this adjustment can differ greatly from person to person—some burn hundreds fewer calories, others burn hundreds more...

Pro

Against

Mechanism

Synthesis from 1 study

How it works

After losing weight, some people’s bodies slow down how many calories they burn, even more than expected from their new size, and this slowdown varies a lot from person to person — the study with DOI 10.1002/oby.23333 shows this happens because hormones and nerves signal the body to conserve...

Most probable mechanism

In Simple Terms

When a person loses weight, their body burns fewer calories than expected based on their new size, and this drop in calorie burning varies a lot between people — some drop a lot, others barely change — because their bodies reduce energy use through hormonal and nervous system signals that slow down metabolism, as shown in the study with DOI 10.1002/oby.23333.

Causal chain

Weight loss reduces fat mass and fat-free mass, lowering the baseline energy demands of metabolically active tissues, as directly measured in individuals following a calorie-restricted diet in the study with DOI 10.1002/oby.23333.

Verified by multiple studies

which leads to

Reduced energy intake and body mass trigger hormonal and neural signals — such as decreased leptin and altered thyroid hormone and sympathetic nervous system activity — that cause a further downregulation of resting metabolic rate beyond what is predicted by body composition changes alone, as directly observed in the study with DOI 10.1002/oby.23333.

Supported by evidence

which leads to

This adaptive reduction in resting metabolic rate creates a smaller daily energy deficit than expected, slowing weight loss and prolonging the time to reach weight goals, with the magnitude of this reduction varying widely among individuals, as quantified by the large standard deviation (±113 kcal/day) and significant individual variation (p = 0.002) in the study with DOI 10.1002/oby.23333.

Verified by multiple studies

Evidence from Studies

Supporting (1)

Community contributions welcome

Metabolic adaptation delays time to reach weight loss goals

Cohort Study

Human

2022 Feb

Contradicting (0)

Community contributions welcome

No contradicting evidence found

Gold Standard Evidence Needed

According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.

Source Study

Metabolic adaptation delays time to reach weight loss goals

Score: 40

DOI: 10.1002/oby.23333

Similar Assertions

After losing 16% of their body weight, women who are overweight and have not gone through menopause tend to burn about 46 fewer calories per day at rest than what would be expected based on their current body size and composition.

81%

When obese individuals lose weight, their bodies burn fewer calories at rest than expected, and this reduction is linked to higher hunger levels, even after accounting for how much weight they lost. This metabolic change returns to normal once weight loss stops and weight stabilizes.

77%

People who reach their weight loss goal faster or slower than expected may do so in part because of how their metabolism adjusts during weight loss, even when accounting for how strictly they follow their diet, how many calories they cut, and how much weight they aimed to lose.

75%

After losing weight, obese adults who maintain higher levels of physical activity and food intake have a slightly higher resting metabolic rate than those with lower activity and intake, resulting in an increase of about 79 calories burned per day at rest.

73%

Among women who are overweight and have not gone through menopause, those whose resting metabolic rate drops more than expected after losing 16% of their body weight tend to take longer to reach a BMI of 25, even when their diet and calorie intake are accounted for.

70%