Cutting Meat, Eggs, Dairy May Activate Fat-Burning Without Exercise, Study Finds

Reducing consumption of meat, eggs, and dairy products alone may increase fat burning in the body, according to a new animal study. Researchers found that restricting intake of specific amino acids boosted heat generation for body temperature maintenance, leading to increased energy expenditure.

According to ScienceDaily and other science publications on the 3rd (local time), a research team at the University of Southern Denmark reported that mice fed a diet low in methionine and cysteine for seven days showed significantly higher calorie expenditure compared to mice on a regular diet. The findings were published in the international journal eLife.

Methionine and cysteine are amino acids abundant in animal-based foods such as meat, eggs, and dairy products. In contrast, plant-based foods including vegetables, legumes, and nuts contain relatively lower amounts.

The research team examined whether body temperature maintenance mechanisms could be activated through dietary changes alone, rather than exposure to cold temperatures. Typically, when exposed to cold environments, the human body generates heat to maintain body temperature, burning calories in the process.

The experiment showed that mice fed the reduced amino acid diet experienced approximately a 20% increase in heat generation within seven days. While food intake and activity levels showed no difference from the control group, these mice lost more weight. The researchers explained that the additional weight loss was due to increased energy expenditure from enhanced heat generation.

The increase in fat burning occurred primarily in "beige fat" located beneath the skin. Beige fat is known to become activated when exposed to cold. The research team analyzed that dietary modification induced fat burning through pathways similar to cold stimulation.

The researchers reported that the weight loss in mice with only dietary changes was comparable to that of mice continuously exposed to cold conditions.

However, this study was conducted on animals. Whether the same effects would occur in humans has not been confirmed.

Jan-Wilhelm Kornfeld, a professor at the University of Southern Denmark who participated in the study, stated, "It would also be worth investigating whether patients taking the obesity drug Wegovy could achieve greater weight loss effects by switching to a diet free of methionine and cysteine—that is, a diet excluding animal protein."

The research team added that future clinical studies in humans will be necessary to verify safety and efficacy.