Effects of Exercise on Appetite and Weight

Do you remember the hubhub over the 2009 TIME magazine article, “Why Exercise Won’t Make You Thin”?  Research is stronger than ever about the importance of regular physical activity to reduce risk of and improve outcomes of diabetes, heart disease and cancer.  What about weight?  Is it the essential kingpin of a strategy to reach and maintain a healthy weight? Or are concerns justified that it could backfire with an increase in appetite?

In this video interview, I’ve gone straight to an expert:  Barry Braun, PhD, Associate Professor at the University of Massachusetts Amherst. He is director of the university’s Energy Metabolism Lab, and his research in this area is widely published.  Please check out our interview and then join in below for discussion.

Some notes on the points Dr. Braun makes in this portion of our interview:

People vary in how their weight changes in response to increasing physical activity.

Just as we respond differently to changes in eating habits, we shouldn’t be surprised that the same change in physical activity can affect people differently.  We are people, not robots.

Some of the differences in results may involve physiological/metabolic differences, others may reflect differences in body composition and in other aspects of overall lifestyle, including eating habits.

Take-home point #1: Don’t compare yourself to others and assume that if a particular change in exercise brought a certain result for someone else it will be the same for you.  Sure, you can get ideas from other people about what has worked for them. Then — since we know that physical activity is vital to so many aspects of health – spend your time and energy focusing on how to best make it work for you.

One reason people don’t lose weight as they expected when they boost activity is that they more than make up for the calories burned in activity by allowing themselves extra food treats.

Over time, the calories we burn up in exercise add up substantially.  However, when you hear about the calories burned by Olympic athletes exercising at maximum intensity for hours every day, it’s easy to forget that’s not the case for most of us.  Most people overestimate the number of calories they are burning by taking a walk.  Treadmills and other gym equipment also often overestimate calories expended.  And it’s all too easy to forget how quickly calories add up from healthy foods in excessive portions and even small portions of “treat” foods concentrated in sugar or fat.

Take-home point #2: Especially considering how very sedentary most of our lives have become, wipe from your mind the thought that you deserve some high-calorie goodie just because you got some exercise.  But you deserve something for your efforts?  You already got it:  you reduced the inflammation and insulin resistance in your body that put you at all kinds of health risks!  The results only last a day or two, but each time you are active, you are doing something good for your body. And don’t you feel some stress reduction and increased energy?  If you don’t, look for another way to be active so you finish it feeling de-stressed and renewed.

Among people most likely not to lose weight when they boost physical activity are Restrained Eaters.

I’ve talked about Restrained Eating in previous blog posts.  The basic concept is that in trying to reach and maintain a healthy weight, we are walking a tightrope.  In today’s world of high-calorie food available 24/7, none of us can eat everything that catches our eye any time we want.  We need to restrict those impulses.  However, when we try to accomplish this with overly rigid rules (“restrained eating”), it often backfires when ultimately we can’t keep it up and end up binge-eating or giving up on healthy eating.

Take-home #3: If this sounds like you, check out my previous post on Flexible vs Rigid Restraint for some ideas on how to walk the tightrope.

Beyond any differences in psychological outlook, research shows metabolic differences between men and women in how they respond to exercise.

Fascinating stuff, this research that Dr. Braun discussed adds another reminder that comparing ourselves to people with a different metabolic makeup gets us nowhere.

Take-home #4: Back to the message to forget about others!  Honor your body by finding a way to get physical activity that works for you, and then use it as one part of a strategy aimed at a healthy weight.

Check back for the next portion of my interview with Dr. Braun in which we talk about what he would say is the ultimate take-home message about exercise and weight control, and whether choices of how we exercise and fuel that exercise make a difference.

References & Resources:

Braun, B. Active Voice: Understanding Physical Activity Guidelines and Weight Loss. Sports Medicine Bulletin. Amer College of Sports Medicine.

Cloud, J.  Why Exercise Won’t Make You Thin. TIME magazine,  Aug 9, 2009.

Nuances in weight control: Are you flexible or rigid (in mindset)?  My Smart Bytes™ blog post from October 26, 2011.