Most individuals who have tried to lose weight have probably heard about the energy balance equation in some form or fashion. The basic idea behind this equation is that our body weight depends upon the balance between the calories we consume through the foods/beverages we eat and drink and the calories we expend through physical activity and normal daily functioning (breathing, heart beating, etc.). Following this equation, if an individual wants to lose weight they need to tip the balance so that more calories are expended than consumed. A pound of fat contains approximately 3,500 calories. Therefore, to lose 1 pound a week we need to burn an additional 500 calories per day through activity or cut 500 calories out of our normal daily intake by modifying what we eat. Sounds simple, doesn’t it? Then why is it so hard for individuals to lose weight?
I strongly believe the reason so many individuals struggle with weight loss is that they overestimate the amount of calories burned during physical activity. In general, it takes a large amount of physical activity to burn enough calories to show actual weight loss on the scale. An average adult burns approximately 100 calories for each mile traveled on foot (not by car). If you therefore go on a 2-mile jog and then come home and eat a bagel with a large glass of orange juice you would have consumed approximately 300 calories more than you burned during your workout (300 calories for the bagel plus 200 calories for the juice vs. expending 200 calories on the jog). Another example, let’s say you participate in a local 5K race and then reward yourself with a milkshake on the way home. You burned approximately 300 calories on your run (a 5K is slightly over 3 miles in length) and consumed close to 600 calories with the shake – and that’s if you ordered the small!
So, does that mean exercise is not important? Absolutely not! Exercise is critical to our overall health and well-being and every little bit of physical activity helps. However, I often hear people saying they exercise so they can eat whatever they want – this is where the problem lies. The focus of our exercise needs to switch from weight loss to health benefits. The 2008 Physical Activity Guidelines recommend that adults participate in a minimum of 150 minutes of moderate intensity aerobic physical activity (i.e. brisk walking) per week and muscle strengthening exercise on 2 or more days per week. These guidelines are based upon health benefits gained from participating in physical activity; greater health benefits can be achieved with activity over these amounts. While it takes a great amount of activity to lose weight by exercise alone, it is a critical factor if an individual wants to maintain weight loss over the long term. Individuals who participate in regular physical activity have more success keeping the weight they lost off. If you are interested in reading the entire 2008 Physical Activity Guidelines for Americans you can do so online at: http://www.health.gov/paguidelines/
So the next time you are considering the extra slice of cheesecake thinking you will jog an extra 10-minutes on the treadmill tomorrow…maybe you will think again.
Food for thought until next time!