Director of Education, VitaMedica
It was hard not to miss the barrage of articles this past week including one in the New York Times critiquing Coca-Cola’s solution to the obesity crisis: get more exercise and focus less on cutting calories. Really?
Coke, like so many other food and beverage marketers, is motivated to divert attention from calorie consumption to lack of physical exercise as the reason for our expanding waistline. However, in the 20 years that I’ve been involved in health and wellness, I have seen limited evidence that physical activity can blunt the surge in obesity.
I work out 6 to 7 days a week so I’m a big proponent of getting exercise. No doubt, physical activity is great for building strength and maintaining muscle mass, elevating mood and preventing against a host of chronic diseases. But, sadly, it does not promote weight loss.
“As a rule of thumb, weight loss is generally 75 percent diet and 25 percent exercise.”
The reality is that if you want to shed pounds, you must cut back on calories. That can be pretty difficult for some dieters which is why I really like meal replacements. Simply by just replacing one meal a day with a high-quality meal replacement – like our LeanMeal RS – multiple studies show that meal replacements can safely and effectively produce significant sustainable weight loss and improve weight-related risk factors of disease.
Quite a few studies have examined the diet versus exercise question and here are some key findings:
Physical Activity Levels of Adults Has Changed Little in Decades
“In the past 30 years, as obesity has rocketed, there has been little change in physical activity levels in the western population. This places the blame for our expanding waistlines directly on the type and amount of calories consumed.” Exercise is good … but it won’t help you lose weight, say doctors
Physically Active Adults Can Still Gain Weight
In the adult population, interventional studies have difficulty showing that a physically active person is less likely to gain excess weight than a sedentary person. To Lose Weight, Eating Less Is Far More Important Than Exercising More
Physical Exercise Burns Fewer Calories Yet Increases Appetite
In a 2012 systematic review of exercise studies, researchers found that only a small amount of weight loss was observed in the majority of studies. This was due to exercisers burning less energy than expected compounded by an increase in caloric intake.
Metabolism Will Drop Even if You Exercise
When you lose weight your metabolism slows down yet it is a common belief that exercise will counter this effect. Research shows that the resting metabolic rate in all dieters slows significantly, regardless if they exercise. In one of the few studies ever to have carefully monitored exercise, food intake and metabolic rates, scientists found that volunteers’ basal metabolic rates dropped as they lost weight, even though they exercised every day. Dieting vs. Exercise for Weight Loss
Calorie Expenditure through Exercise is Relatively Small
We spend most of our calories every day just “staying alive.” This is known as our resting metabolic rate. For a 150 pound woman with 30% body fat, she burns more than 1,700 calories from everyday activities. Burning a few hundred extra calories from exercise will not make a big dent in overall caloric consumption. Exercise vs. Diet: Which Is More Important for Weight Loss?
Exercising Without Dieting is Tiring & Your Body Will Compensate
Samuel Klein, MD at Washington University’s School of Medicine says, “If the exercise made you tired so that you become more sedentary the rest of the day, you might not experience any net negative energy.” Some of the calories we burn come from our basic movements throughout the day – so if you’re wiped out after exercise, and more likely to sit on the couch afterwards, you’ve lost the energy deficit you gained from your jog.” The 6 Weight-Loss Tips That Science Actually Knows Work
Biggest Short Term Weight Loss Results is from Eating Smart
Shawn M. Talbott, PhD, nutritional biochemist and former director of the University of Utah Nutrition Clinic says, “As a rule of thumb, weight loss is generally 75 percent diet and 25 percent 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 23 pounds; the exercisers lost only six over about 21 weeks.
It’s much easier to cut calories than to burn them off. For example, if you drink a Starbuck’s Caramel Frappuccino Venti, it can pack on 510 calories. You’ll need to run at 6 mph for over an hour to burn off that coffee drink. While diet and exercise are both important for long-term weight loss, remember this: “You can’t out-exercise a bad diet,” says Talbott. Exercise Vs. Diet: The Truth About Weight Loss
Greater Weight Loss From Dieting Alone than by Exercise Alone
Samuel Klein, MD at Washington University’s School of Medicine says, “Decreasing food intake is much more effective than increasing physical activity to achieve weight loss. If you want to achieve a 300 kcal energy deficit you can run in the park for 3 miles or not eat 2 ounces of potato chips.” It’s as simple as that. Some studies have borne out this dichotomy, pitting exercise against diet and finding that participants tend to lose more weight by dieting alone than by exercise alone. Of course, both together would be even better.” The 6 Weight-Loss Tips That Science Actually Knows Work
Focusing on Diet is Easier than Working Off the Extra Calories
“It’s clear that you need to restrict calories in your diet to lose weight—and exercise to keep it off,” says Tim Church, M.D., the director of preventive medicine research at Louisiana State University, in Baton Rouge. “Most people who exercise to lose weight and don’t restrict calories shed only 2 to 3 percent of their weight over 6 to 12 months,” says Church. The reason? It’s much easier to cut back on 500 calories a day—the amount you typically need to cut to lose a pound a week—than to burn that much through exercise. For instance, to work off almost 500 calories, a 155-pound woman would have to spend an hour on the elliptical machine. Which Impacts Your Weight More: Diet or Exercise?
To Kick-Start Weight Loss, You Need to Diet
“To lose weight initially, emphasize reducing calorie intake rather than increasing physical activity,” says Louis Aronne, MD, obesity expert at New York–Presbyterian Hospital/Weill Cornell Medical Center. A study from the University of Missouri–Columbia found that participants who attended Weight Watchers meetings for 12 weeks lost an average of 5 percent of their body weight (about 9 pounds); those who just joined a gym shed only about 3 pounds. Which Is Better for Weight Loss: Diet or Exercise?
Having said the above, one of the most important benefits of exercise, is the role it plays in weight maintenance.
To Maintain Weight Loss, Focus on Exercise
People who regularly work out are nearly twice as likely to keep pounds from piling back on as those who don’t, says research in the American Journal of Preventive Medicine. “When you exercise, you activate hormones that tend to favor using more fat as fuel,” says Pamela Peeke, MD, author of Body for Life for Women and assistant clinical professor of medicine at the University of Maryland School of Medicine.
Holly Wyatt, MD, medical director of the Anschultz Health and Wellness Center at the University of Colorado notes, “Regular exercise gives you a little leeway, but it won’t cover 3,000-calorie meals.” Bottom line: Cut calories to lose weight. But add in some activity to stay slim long term. Plus, exercise can boost your mood and energy. Which Is Better for Weight Loss: Diet or Exercise?
Exercise is Critical in the Weight Maintenance Phase
Michael Jensen, MD at the Mayo Clinic says “Exercise buys us some wiggle room. Exercise is very, very important for maintaining lost weight, and people who are not physically active are more likely to gain weight.” The 6 Weight-Loss Tips That Science Actually Knows Work
The bottom line is that both diet and exercise are important for achieving and maintaining a healthy weight. However, getting control of what you eat is 75% of the battle when it comes to weight loss. Then, once you’ve lost the weight, physical exercise plays a bigger role in keeping the weight off – a challenge that many dieters seem to have.
Last updated March 7, 2016
David H. Rahm, M.D. is the founder and medical director of The Wellness Center, a medical clinic located in Long Beach, CA. Dr. Rahm is also president and medical director of VitaMedica. Dr. Rahm is one of a select group of conventional medical doctors who have education and expertise in functional medicine and nutritional science. Over the past 20 years, Dr. Rahm has published articles in the plastic surgery literature and educated physicians about the importance of good peri-operative nutrition.