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Research: Sex differences in fat metabolism
A new study has found major differences in the way males and females utilise fat during exercise, as Kath Hudson reports
The way fat stores are metabolised during exercise is different in males and females, according to a US study, which shows the need for more research into how exercise impacts the female body.
Published in the journal Nature Metabolism, the research was undertaken by the Molecular Transducers of Physical Activity Consortium, a collaboration of more than 100 scientists across a number of universities, studying the molecular changes which occur during and after exercise to advance the understanding of how physical activity improves and preserves health.
While exercise changes the health of fat stores in both sexes, making them more metabolically active, scientists discovered vast differences in the way fat tissues in males and females responded to running on a treadmill over an eight week period.
While males burned fat for energy, females were more likely to preserve and ‘recycle’ their fat mass.
Although females burned fat at the start of the trial, by the end of eight weeks their fat stores had reverted to how they had been at the start, although they did not gain fat in the way their sedentary counterparts did.
Getting energy in different ways
“We saw both sexes mobilise their metabolism to get the energy they need,” said first author Gina Many. “But they get their energy in different ways. Females do so without drawing so much from their fat stores, likely because these are critical to reproductive health.”
While too much body fat can cause disease in some people, depending on how and where their body stores it (with this differing according to body type and genetics), having body fat is also important for health, as it controls parts of the endocrine system, among other things.
In recent decades, scientists have learned that fat isn’t just unwelcome weight, but a major organ that runs through the body. Like the skin, it secretes hormones and other compounds that play an important role in our health.
Ovulation and menstruation typically stops if women’s body fat drops below 18 per cent, with 22 per cent currently thought to be the optimum level.
“These findings help set the landscape to understand disease risk and establish a basis for more personalised and targeted health interventions,” said Many.
Equitable health studies
The results also highlight the need for health studies to include males and females, as traditionally research has been heavily skewed towards males.
