October 2015 Issue

Dieting Myths Debunked

Set yourself up for more successful weight loss by discarding these common diet misconceptions.

When you’re desperate to drop a dress size (or two), it’s easy to latch onto inaccurate notions about what it takes to lose weight or to assume that what worked for your friend will work for you. The reality is that there’s no magic bullet for weight loss, and diets aren’t one-size-fits-all. EN asked experts to clear up common myths.

MYTH 1 - You’ll lose one pound for each 3,500 calories you cut. If you’ve spent any time with your nose in diet books, you’ve likely encountered the “rule” that says cutting 500 calories a day will give a weight loss of one pound a week (500 x 7 days = 3,500 calories). This oversimplified calculation is outdated. “As you lose weight, your body needs fewer calories to run, for example, for your heart to beat and for you to move around, so your weight loss will slow over time,” says Diana Thomas, PhD, director of the Center for Quantitative Obesity Research at Montclair State University in New Jersey.

“The 3,500-calorie rule also fails to account for other factors that impact how quickly people lose weight, such as how much extra fat they have, how old they are, and their gender,” Thomas says. To get a more accurate prediction of your weight loss over time, use the easy calculator at weight-loss-predictor.appspot.com/weight, which Thomas helped develop.

MYTH 2 - Weight loss just requires eating less and moving more. “It can be more challenging to lose weight than some people think, and environmental toxins called obesogens may be one reason why,” says Sara Gottfried, MD, author of The Hormone Reset Diet. Many chemicals used in everyday items, such as BPA (bisphenol A) in plastic food containers, phthalates in fragrances, and flame retardants in sofas, may disrupt hormones that influence weight control.

“For example, BPA acts as a fake testosterone, which can contribute to polycystic ovary syndrome (PCOS) and interfere with insulin signaling in women,” Gottfried says. PCOS is a hormonal disorder that affects at least 10 percent of women and can make weight loss and blood sugar control more challenging. More research is needed to confirm the link between environmental toxins and PCOS.

Although we can’t avoid all man-made chemicals, Gottfried advises finding fixes for areas where you get the most chemical exposure or spend the most time. For example, buy an eco-friendly sofa that’s free of flame-retardant chemicals (and spend less time sitting, too). Use glass containers instead of plastic to store food. Choose fragrance-free personal care and household products. Get more ideas at ewg.org.

MYTH 3 -  Eat gluten-free to lose weight. “Some people think eating gluten-free will help them lose weight, especially women with PCOS,” says Angela Grassi, MS, RD, founder of the PCOS Nutrition Center in Bryn Mawr, Pennsylvania. “Although some people do find they lose weight by avoiding gluten, it really could be due to cutting calories, such as passing up the bread basket at a restaurant. Or, they may actually have a gluten sensitivity, so removing gluten from the diet reduces inflammation and fluid retention. But certainly not everyone who eats gluten-free will find it helps them lose weight. It’s more important to focus on eating fiber-rich fruits and vegetables, whole grains, and protein-rich foods to help balance blood sugar.”

MYTH 4 - You should take a cheat day. Some diet plans advise taking a “cheat day” to reward yourself for sticking to your regimen the rest of the week. “Taking an entire day to splurge is a bit excessive and could derail your plan,” says Jennifer McDaniel, MS, RDN, CSSD, who has a private practice in St. Louis, Missouri, and is a spokesperson for the Academy of Nutrition and Dietetics. “Data from the National Weight Control Registry tells us that people who successfully maintain their weight loss have similar eating patterns seven days a week.”

“However, that doesn’t mean you can’t budget for a cheat meal, such as a birthday party,” McDaniel adds. “It also can help to plan for something small every day that feels like a cheat, such as 100 calories-worth of dark chocolate, so you don’t feel deprived. Planning your splurge also gives you motivation to turn down other treats.”

MYTH 5 - Exercise entitles you to eat more. “Many people think they’re burning an exorbitant number of calories with exercise. In reality, they may be burning only 120 calories in their strength-training regimen and haven’t changed anything else in their sedentary lifestyle. So, small increases in their food intake will undo the calorie deficit they aimed to create,” McDaniel says. “Reducing calories is primarily what drives weight loss, while exercise really plays a bigger role in helping maintain weight loss.”

Adding to misconceptions about exercise's impact are fitness machines and charts that tell you how many calories you burn with a certain activity. “An elliptical machine or online exercise calculator often overestimates how many calories you’ve burned because it doesn’t account for all of the individual factors, such as your percent muscle mass and heart rate, which are needed to provide an accurate count,” McDaniel explains.