Looking To Curb Hunger? Cardio Exercises Like Running May Work Better Than Healthy Eating

Running Weight Loss
When it comes to cutting calories, exercise works better for staving off hunger than maintaining a healthy diet. Photo courtesy of Getty Images/Bloomberg

Losing weight is one of the top goals of more than half the American population, yet the verdict is still out on whether they should invest more time into their diet or exercise. A team of scientists from Loughborough University in England put a group of men and women to the test and published their findings in the journal Medicine & Science in Sports and Exercise.

Eating healthier has its perks, but researchers wanted to find out if it had the ability to keep calories low in order for participants to successfully lose weight. When comparing the two, researchers found exercise is more likely to stave off hunger than a healthy diet ever could.

For the study, researchers conducted two experiments. In the first, 12 healthy women were recruited and assigned to either restrict their diet by providing a healthy carbohydrate-to-protein and fat balance or exercise by running on a treadmill for 90 minutes. They repeated the experiment in three trials. Afterwards, participants were placed in front of a buffet and given permission to eat as much food as they desired. Meanwhile, their hormonal, psychological, behavioral responses, calorie intake, and appetite ratings were monitored over the course of nine hours.

Researchers found the women who had undergone food restriction had increased levels of the hunger hormone ghrelin, which releases a chemical in the stomach that sends hunger signals to the brain. The same women who had restricted diets also had lower levels of a hunger suppressing hormone peptide YY, which releases chemicals into the bloodstream and stomach and makes its way up to the brain where it influences eating and drinking behaviors. But the same hormone fluctuations were not seen for participants who were assigned to strictly exercise. When it came down to how much they ate, participants who underwent food restrictions ate an average of 944 calories compared to exercisers who ate only an average of 660 calories.

In the second experiment, researchers replicated the food restriction and exercise regimen except they recruited 10 men and 10 women to undergo two, 7-hour trials with 60 minutes of running. Participants exhibited the same results as in the first experiment and there was no difference between how men and women reacted to each scenario.  

"Our findings provide a valuable contribution to the diet and exercise debate,” said the study’s lead author Dr. David Stensel, a scientist at the University’s National Centre for Sport and Exercise Medicine East Midlands, in a press release. “We've shown that exercise does not make you hungrier or encourage you to eat more — at least not in the hours immediately following it.”

Next, researchers plan on conducting a long-term study to see if the same effect holds true beyond the first day of exercise, or if food restriction is the more sustainable way to cut calories and keep them limited.

A 2013 study, published in the International Journal of Obesity, revealed the intensities of workouts may also influence calorie intake. Overweight men were assigned to either moderate, high, or very high intensities on stationary bikes for 30 minutes. Afterwards, participants ate 710 calories after moderate exercise, 621 calories after a high intensity workout, and 594 calories after the highest intensity workout.

In the end, researchers from both studies conclude that a high-intensity workouts’ ability to suppress and curb appetite and cravings may be more important to successful weight loss than simply cutting calories.

Source: Stensel DJ, Alajmi N, and Deighton K, et al. Appetite and Energy Intake Responses to Acute Energy Deficits in Females versus Males. this month in Medicine & Science in Sports and Exercise. 2016.

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