Less may be more when it comes to keeping slim.

A new study by the London School of Economics found that people are "more likely to have a lower weight if they regularly engage in high impact walking compared to doing another vigorous activity like going to the gym."

The specialist in health economics who led the research examined reported physical activity levels from an annual health survey in England from 1999 to 2012, and then analyzed data collected by nurses on body mass index (BMI) and waist circumference measurements.

It found that men and women who regularly walked briskly for more than 30 minutes had smaller waists and lower BMIs than those who did regular sports or exercise.

"That's a hugely counterintuitive finding, and not at all what we would've expected, and this is even correcting for how much are people eating," said Dr. Brett Belchetz, an emergency room physician and a medical columnist on North by Northwest.

"For any given person with the same dietary intake, the person who is just briskly walking, on average is a slimmer person that the person who is doing all of this extreme exercise."

Different for men

However, Dr. Belchetz said the study found that though the results were consistent in women of all ages, that wasn't the case for men.

The results were the same in men over 50 years old, but men under 50 "tended to be actually slimmer sometimes when they were doing the more vigorous exercise."

Dr. Belchetz also pointed to another study, published in the Journal of the American College of Cardiology in February 2015, which looked at data for about 1,000 people over 12 years and found that the ideal amount of jogging to prolong life was between one and 2.4 hours a week, and at a slow pace.

"The runners who were running the most, and the most vigorously, so those who were running at an average pace of seven miles per hour or faster, and running for more than four hours per week, actually had mortality rates that were just as bad as the couch potatoes that never got off the couch.

"So they were undoing all of the benefit of exercising, by exercising too much."

Moderation

Dr. Belchetz said the advice he takes from the London School of Economics study is "everything in moderation."

"When it comes to exercise you cannot be that sedentary person on the couch, do not throw away your gym membership based on this study, but don't go out there and try and be a marathon runner.

"There's a healthy level of exercise which is exercising about three to four times a week, never more than about 30 minutes per exercise, or even less than that is enough and if you do it at that moderate pace not only are you going to help yourself lose weight more effectively, you're probably going to make yourself live longer."

To hear the full interview listen to the audio labelled: ER physician discusses study that says brisk walking may be better than vigorous exercise for losing weight