Your gym hours mightnot prevent weight gain

NO PAIN NO GAIN: Increased activity boosts appetite and may lead to greater weight gain and periods of inactivity. Picture: Bluetooth Special Interest Group

NO PAIN NO GAIN: Increased activity boosts appetite and may lead to greater weight gain and periods of inactivity. Picture: Bluetooth Special Interest Group

Published May 4, 2017


You've been doing all you can, putting in the long hours and sweating at the gym in an effort to lose weight. However, instead, you’re gaining weight.

Take heart, as new evidence shows that physical activity or exercise may not necessarily protect you from gaining weight.

The study, titled “Accelerometer-measured physical activity is not associated with two-year weight change in African-origin adults from five diverse populations”, was conducted by the University of Loyola in Chicago.

The study was published in the journal PeerJ.

It included 2500 participants aged between 25-45, from South Africa, Ghana, Seychelles, US and Jamaica and found neither physical activity nor sedentary time were associated with weight gain.

Health experts have long advocated for an increase in levels of physical activity as a strategy in lowering obesity levels.

And the benefits of exercise on curbing non-communicable diseases are well-documented, as well as its benefits on mental health and mood.

However, while physical activity burns calories, it also increases appetite, and people may compensate by eating more or by being less active the rest of the day.

Participants wore tracking devices called accelerometers on their waists for a week. The devices measured the wearer’s energy expenditure and step count.

Researchers also measured participants’ weight, height and body fat. After an initial exam, participants were asked to return one year and two years later.

The study showed that physical activity was not associated with the future weight gain of the participants after a two-year follow up with them.

At the initial measurements, the lowest weights captured were among men from Ghana and South Africa at an average of 63kg and 64kg, respectively, and the highest among US men and women at an average of 93kg and 91kg, respectively.

The researchers categorised participants at each site by whether they met the US Surgeon General guidelines for physical activity at 30 min/day on most days of the week.

“Among the men, over 76% of Ghanaians (N=158) and South Africans (183) met the guidelines, compared to only 44% of US men (109).

“Far fewer women met this guideline, with only 44% of Ghanaian women (130) compared to about 20% of US women (50),” the study said.

Surprisingly, researchers said, the total weight gain at every site were greater among participants who did meet the physical activity levels than those who didn’t.

Similarly, among the women, at each site, weight gain was less among the participants not meeting the physical activity guidelines, for example among South African women meeting the guidelines the yearly weight gain was 1.8kg/yr vs. 0.7kg of those who didn’t.

“Importantly, this is not to say physical activity is not important for overall achievement of health such as the prevention or delay of diabetes and cardiovascular disease, which is undisputed, but that its role in the prevention of population level weight gain may be overstated,” the study noted.

Researchers involved in the study said their data suggested “other environmental factors that influence food consumption” may be a more fertile field for public research and health intervention.

Health and wellness expert, Vanessa Ascencao, said South Africans should educate themselves on a healthy lifestyle and practise a more mindful attitude to life.

She added that eating healthily should be seen as an investment rather than a burden.

“The vast benefits of living healthily include reducing the risk of depression, obesity, diabetes, diseases and improving overall quality of life,” she said.

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