Interestingly, the study talks about the prevention of weight gain, not weight loss, but I'm sure the conclusions would be similar if the study looked at weight loss. Except that (sorry to say!) even more exercise is probably needed for weight loss because we're trying to create a calorie deficit instead of just staying in calorie equilibrium, like we would for maintenance. So we need even fewer calories than for maintenance of weight.
In my experience with myself and personal training clients, exercise is an absolute imperative as we get older. It's almost impossible for women my age (55) to create a sufficient calorie deficit without exercise in order to lose weight. And it's very, very hard to restrict calories to a maintenance level without exercise.
For example, right now I maintain at about 1400 - 1600 calories a day, with about 90 minutes of daily exercise. If I didn't exercise, my maintenance calories would probably be in the neighborhood of 1000 calories a day, which for me, would be completely unsustainable for the long haul. No thanks! There are so many benefits to exercise besides weight loss and maintenance that it's a no-brainer to pick eating more with more exercise over eating less without exercise.
Putting aside weight, exercise is the Fountain of Youth for us older women. We build strong bones, get rid of toxic belly fat, have shapely arms and perky butts, keep our metabolisms running high, wear smaller sizes, and have healthy cardiovascular systems with exercise (and don't forget that heart disease is still the number one killer of women!) The weight loss and maintenance benefits are a bonus, but exercise is something we all should have in our daily lives, regardless of our weight.
another study on exercise and weight loss
