Which Makes More of an Impact in Losing Weight: Diet or Exercise?

I’ve actually got four answers to this question:

1. Initially it’s diet, but long term it’s a combination of both
2. Exercise alone typically does not make much impact in weight loss
3. However, exercise helps you keep the weight off long term
4. There are other benefits to exercise you don’t get with dieting alone.  Exercise improves your health, keeps your body strong and functional, and helps with stress, cognitive function and mood.

In researching this topic one of the first places I went was the National Weight Control Registry (NWCR), which is a listing of over 10,000 people who have lost significant amounts of weight and kept it off.  The NWCR analyzes (among other things) what these successful losers have done.  Of these people:

• 1% used exercise alone to lose weight
• 10% have had success using diet alone
• 89% use a combination of diet and exercise

One of the reasons why diet alone INITIALLY makes a large impact on weight loss is time.  The choice NOT to drink a full calorie soda (150 calories) takes seconds to make.  However, it would take 10 minutes of running or 30 minutes of walking to burn those calories.  One slice of Domino's pepperoni pizza (284 cal) would require about 25 minutes of swimming.  As you can see, it’s faster to create a calorie deficit by restricting calories than it is to exercise.

WHAT TO DO: While guidelines suggest 1 to 2 pounds of weight loss a week, you should set a goal that is both realistic and manageable for your lifestyle and fitness level. Overly aggressive goals often backfire.

1.  For long term success plan to use both calorie restriction as well as an increase in physical activity.

2.  Be consistent with your eating plan across the week.  Instead of dieting more strictly throughout the week and then relaxing on the weekend, keep things consistent.  Research shows consistency is better for the long haul.

3.  Spread your total calorie intake throughout the day. Eat a reasonably sized meal or small snack about every 3-4 hours instead of only eating 1-2 times each day.  Grazing prevents you from getting too hungry and accidentally overeating as well as keeping your metabolism running strong.

4.  With exercise and activity, people who successfully maintained weight loss exercised an average of an hour or more per day.  This may seem like a big commitment so keep these things in mind:

• Accumulate time. You do not have to do 60 minutes all at once and can build it up throughout the day.
• Start where you are and add on.  If you’re currently doing 15 minutes of exercise 3 times per week add another 3-5 minutes to each workout or add another day of exercise.
• Time vs. energy.  It’s not the time you spend exercising that makes the most difference; it’s what you do in the time you have.  By increasing the intensity of your workout you’re increasing the number of calories you burn.  You could walk at a moderate pace for 30 minutes or walk at a faster intensity and burn the same amount of calories in a shorter period of time.

5.  Exercise is not an excuse to eat whatever you want.  It’s easy to rationalize having an extra helping at dinner or imbibing in a special treat because you worked out and you’ve “earned” it.  We often underestimate the amount of calories we eat and can end up gaining weight if this is the excuse we use to be more relaxed about what we’re eating.

6.  Aim to reduce calorie intake by 10-15% each day.

• Eat off a smaller plate.
• Split a meal when eating out or put 1/2 of it in a to-go box before beginning to eat.
• Make swaps. Instead of regular sliced bread use a sandwich thin.  Swap a lean source of protein like pork, chicken or beans for beef.  Instead of 2% milk switch to skim.  Drink carbonated water instead of soda.

A couple of other important statistics of successful losers from the NWCR:

• 78% eat breakfast every day
• 62% watch less than 10 hours of TV per week
• 90% exercise, on average, about 1 hour per day
• 75% weigh themselves at least once a week