It’s an age-old debate – which is more important for weight control, diet or exercise? According to some studies, diet, what you eat and how much, is more important than physical activity for weight loss. Proponents of this idea point out that noshing down on a brownie after an exercise session is enough to compensate for the calories and sweat you shed during a workout. No doubt about it – it’s easy to out eat a workout, but exercise offers weight control and anti-aging benefits that nutrition doesn’t.
Exercise for Weight Control
It’s also no secret that people gain weight as they age and lose muscle mass. In women, this process accelerates after menopause. Gaining body fat isn’t just a cosmetic problem – weight gain after menopause is a risk factor for health problems, including breast cancer and type 2-diabetes. Plus, women gain visceral fat post-menopausally, the type of abdominal fat linked with health problems such as heart disease and type 2 diabetes. Visceral fat is hormonally active itself, producing hormonal factors that encourage inflammation.
So is diet more important than exercise for shedding body fat later in life? A new study, involving almost 5,000 adults between the ages of 20 and 70, questions this idea and shows that exercise is actually MORE important than what you eat. This study used information like levels of physical activity (measured by accelerometer), BMI, waist size and body weight from the National Health and Nutrition Examination survey to see what effect diet/exercise had on weight gain over time. It showed a lack of physical activity is a stronger contributor to weight gain than diet as people age. This study has stronger credibility than many studies because activity levels were measured rather than derived from self-reports, which are notoriously inaccurate.
Why Exercise is So Important as We Age
It sounds so simple in theory. To control your weight, cut back on how much you eat, choose more low-calorie food options and reduce the amount of sugar and rapidly absorbed carbs from your diet. Yes, all of these things HELP with weight control, but it’s not necessarily a sustainable plan. You can only reduce your calorie intake so much without missing out on essential nutrients you need for optimal health and to feel your best. Plus, your body adapts to dietary changes and your metabolism may slow over time when you restrict calories too aggressively.
Then there’s the metabolic slowdown that comes with age. As lean body mass decreases, you lose metabolically active muscle tissue, the very tissue that stimulates fat burning. Along with the loss of muscle, insulin sensitivity decreases and insulin levels rise, slowly turning your body into a fat storage machine. How does exercise help? Resistance training reduces the loss of lean body mass and improves insulin sensitivity, so you’re less likely to gain body fat as time goes by. A study published in Sports Medicine showed aerobic exercise and resistance training BOTH increase insulin sensitivity, but resistance exercise has the added benefit of building metabolically active muscle tissue as well.
Exercise for Weight Control Maintenance
What’s more challenging than losing weight? Maintaining it, of course. The overwhelming majority of people who lose significant amounts of weight gain most or all of it back over time. Some gain even more than they had originally! One reason is the drop in metabolic rate you experience after losing weight as your body tries to get you back to your “set point” weight. Work up a sweat regularly and you avoid this frustrating side effect most people experience when they lose weight. A study published in Medical Science Sport and Exercise showed exercise reduces the drop in energy expenditure that comes with weight loss. As you can see, calorie restriction slows your metabolism while exercise, especially resistance training, speeds it up.
Hormonal changes make it harder to control your weight with age. We already talked about how insulin sensitivity decreases and makes it harder to control your weight. You also produce less growth hormone with age and this makes it harder to shed body fat and build lean tissue. Metabolic workouts and resistance training augment the release of growth hormone. The best formula for boosting growth hormone release is high-intensity training, both aerobic and resistance. Some research suggests you can boost growth hormone release after a workout even more by consuming carbs and whey protein immediately after a sweat session.
The Bottom Line
Fortunately, there no need to choose between eating healthy and exercise. Why not do both? Each is important for weight control and for health and longevity. The take-home message is: Nibbling on a salad to control your weight as you age isn’t enough. You need the added benefits that vigorous exercise and weight training offer. Exercise helps to preserve muscle tissue and bone mass and gives your metabolism a kickstart as it helps you stay vibrantly functional. It’s a natural anti-aging prescription and one that too few people take advantage of.
Yet even regular physical activity doesn’t give you carte blanche to eat whatever you want. It’s hard to “out-exercise” a bad diet and easy to undo the negative calorie balance you created through exercise by eating a calorie-laden post-workout snack. Think of exercise and nutrition as complementary approaches to achieving health, weight loss and maintaining your weight as you age. Together, they’re more powerful than either one alone and both become even more important as you grow older. Stay physically active and eat to support your active lifestyle.
References:
BMJ. 335(7630):1134, 2007.
Sports Med. 2003;33(8):599-613
Climacteric. 2012 Oct;15(5):419-29. doi: 10.3109/13697137.2012.707385.
Sports Med. 2000 Nov;30(5):327-46.
Sports Medicine. November 2000, Volume 30, Issue 5, pp 327-346.
Journal of Gerontology. 2001, Vol. 56A, No. 10, B449-B455.
Med Sci Sports Exerc. 2015 Jan 20. [Epub ahead of print]
Peak Fitness. “Study: Both Exercise and Whey Augment Human Growth Hormone Production, Which Can Keep Your Body Young”
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