When female mice eat a diet full of fat for a month, they get much heavier than mice eating a normal diet, and this starts happening after just two weeks.

Scientific Claim

Feeding female ICR mice a high-fat diet (60% kcal from fat) for four weeks is associated with significantly greater body weight gain compared to a control diet (10% kcal from fat), with differences becoming significant by week two and persisting through week four.

Original Statement

“HF mice weighed more (P<0.05) after week two, BMI and percent body fat was greater (P<0.05) in HF than CON at the end of wk 4.”

From study:High fat diet induces obesity, alters eating pattern and disrupts corticosterone circadian rhythms in female ICR mice

Evidence Quality Assessment

Claim Status

appropriately stated

Study Design Support

Design supports claim

Appropriate Language Strength

association

Can only show association/correlation

Assessment Explanation

The study design (non-randomized cohort in mice) cannot establish causation, but the data show a clear, statistically significant association. The verb 'is associated with' correctly reflects the evidence level.

Evidence from Studies

Supporting (1)

High fat diet induces obesity, alters eating pattern and disrupts corticosterone circadian rhythms in female ICR mice

Cohort Study

Animal

2023

The study found that female mice eating a very fatty diet got much heavier than mice eating a normal diet, and the difference showed up after just two weeks and kept growing — exactly what the claim says.

Contradicting (0)

No contradicting evidence found

Source Study

High fat diet induces obesity, alters eating pattern and disrupts corticosterone circadian rhythms in female ICR mice

Score: 15

DOI: 10.1371/journal.pone.0279209

Similar Assertions

At first, the mice on the fatty diet ate the same amount of food by weight as the others, but still got more calories because fat is energy-dense.

95%

Even if they eat the same amount of food by weight, mice on a fatty diet take in way more calories because fat has more energy than other nutrients.

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Mice on a fatty diet not only weigh more, but also have a lot more body fat and a higher BMI, meaning they’re much fatter than mice on a normal diet.

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Mice that eat a high-fat diet start snacking more during the day—when they normally sleep—and eat less at night—when they normally are active.

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The natural daily rise and fall of the stress hormone in the mice’s poop becomes flatter and stays higher all day when they eat a fatty diet.

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