Ask the Specialty Pharmacy Expert – Neda Asli


Ask the Specialty Pharmacy Expert – Neda Asli

Diet vs. Exercise

When it comes to losing weight, one of the most common arguments I hear is exercise vs diet; which one is more effective and which is key for weight loss?

Studies suggest that cutting calories through dietary changes promotes weight loss more effectively than exercise and physical activity, but physical activity is also important in weight control. In an attempt to define the role of exercise in the treatment and prevention of obesity, the American College of Sports Medicine (ACSM) held a scientific roundtable to address this subject. They claim that physical activity without caloric restriction minimally, if at all, affects fat loss. Their statements also suggest that to optimize weight loss, a combination of diet and exercise is best, and that exercise alone will not suffice.

As a rule of thumb, weight loss is generally 75% diet and 25% exercise. An analysis of more than 700 weight loss studies found that people see the biggest short-term results when they eat smart.

On average, people who dieted without exercising for 15 weeks lost 23lbs. People who exercised without dieting lost only 6lbs over 21 weeks. It’s much easier to cut calories than to burn them off. For example, if you eat a fast-food steak quesadilla, which can pack 500-plus calories, you need to run more than four miles to ‘undo’ it!

Why Exercise-Focused Regimens are Relatively Ineffective for Weight Loss?

Reason 1. Calorie expenditure through exercise is relatively small in the grand scheme of things.

We spend most of our calories every day just “staying alive.” This is known as our “resting metabolic rate.” Let’s say you are a 200 pound man who is at 30% body fat. You expend 1,743 calories per day just staying alive. Now, add another 20% for getting out of bed and going about your daily routine and you’ve already burned 2,300 calories. Adding exercise into the equation barely makes a dent in your overall caloric expenditure; most of the work is done before you put on your running shoes. Now I am not saying that you shouldn’t exercise, but rather it’s important to realize where the majority of your caloric expenditure is coming from.

Reason 2. People are horrible estimators of calories in vs. calories out.

In a study in the Journal of Sports Medicine and Physical Fitness, researchers asked the subjects to exercise, estimate their caloric expenditure, and then took them to a buffet afterwards. Subjects were asked to consume the amount of food that they believed they burned in calories.

The subjects ended up eating 2-3 times the amount of calories that they burned.

The takeaway from all of this information is that calorie expenditure doesn’t count for much, and human beings are generally terrible at estimating both expenditure and intake.

Most people I see struggle far more in their kitchens than in their gyms. They will readily find 30 minutes or more a day to hit the gym, go for walks, or simply up their daily activity by parking further away and taking the stairs more often, than they will for packing a lunch, prepping ingredients, cooking dinner, or keeping a food diary. It is so critical for weight loss to watch what you are putting into your body. Time spent on prepping healthy, nutrition-rich food and cutting sugar and calories out of your diet will have a significantly greater affect on your weight loss goals that hitting the gym for 30 minutes.


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