The Fat-Free Truth
Real Answers To The Fitness And Weight-Loss Questions You Wonder About Most

By Liz Neporent, M.A., and Suzanne Schlosberg

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The Whole Truth And Nothing But The Truth

Is it true? That's the question that probably comes to mind every time you read or hear a claim about a new diet plan, metabolism-boosting pill, exercise device or workout regimen. You wonder: Has the Atkins diet really been vindicated by scientific research? Will Pilates give you "long, lean muscles - no bulk," like some of the Web sites promise? If you pack on three pounds of muscle, will you actually burn an extra 10,000 calories a month?

Of course, your own common sense tells you the promises can't all be true. Indeed, there's no shortage of exaggerations and misconceptions floating around the media and the gym, and there's plenty of conflicting advice. That's why Liz Neporent and Suzanne Schlosberg, authors of Fitness for Dummies and Weight Training for Dummies, have teamed up for the third time. In The Fat-Free Truth, published by Houghton Mifflin, they offer straight-shooting answers to the workout and weight-loss questions that you wonder about most - some 240 questions in all.

They've ignored the hype, scrutinized the studies, and quizzed top researchers, not settling until they've gotten to the bottom line. Among the questions they tackle: How can I boost my metabolism? What's the best way to get rid of a paunchy middle? What are the chances of regaining weight after liposuction? Will I sweat more - or less - as I become more fit? And just in case you find yourself stymied for conversation at a cocktail party, they've also tossed in some fitness trivia questions. Next time you need an ice-breaker, try this one out: "Say, does anyone know how the marathon came to be 26.2 miles?"

From The Pages Of The Fat-Free Truth

Low-carb diets, weight-loss surgery, Pilates, weight training, home exercise equipment, metabolism, postpartum weight loss - these are just some of the topics covered in The Fat-Free Truth. Here's a sampling of the questions you'll find in the book.

Question #5: To what extent is my weight influenced by my genes?

The short answer: On average, research suggests, a person's weight is probably a bit more than 50 percent influenced by genetic factors. However, in certain populations the environment plays a larger role.

When you see a family in which every member is as slim as Lara Flynn Boyle, you may wonder: Are they svelte because they're genetically programmed to be or because they go on family hikes and never set foot in Burger King? The influence of genetics and the environment on weight is an issue that scientists have been trying to sort out for decades.

A wealth of knowledge has come from research on identical twins, who, of course, share all the same genes. In a classic Canadian study published in the New England Journal of Medicine, researchers sequestered 12 sets of identical male twins for 100 days at a college dorm. Six days a week, the twins were fed 1,000 calories per day more than they needed to maintain their weight; other than walking for 30 minutes daily, the subjects did virtually no physical activity. At the end of the study, each subject had consumed 84,000 extra calories - enough, theoretically, to gain about 24 pounds (since it generally takes an 3,500 extra calories to gain 1 pound of fat).

But that's not what happened: Some men gained as little as 9.5 pounds whereas others gained as much as 29 pounds. The difference in weight gain between the various twin pairs was three times greater than the average difference within the pairs. The location of the extra fat deposited - whether below the waist, deep in the belly, or beneath the skin in the abdominal area - also was similar within the pairs but varied greatly between pairs.

Research comparing twins raised apart and twins raised together confirms the significant influence of genes on body fat. In a study of some 600 Swedish twins, the Body Mass Index scores of identical twins raised apart were just as similar as BMI scores of identical twins raised together. And the BMI scores within identical twin pairs were far more similar than the BMI scores within fraternal twin pairs. The researchers concluded that, at least in Western society, genetic factors may account for as much as 70 percent of weight differences between individuals.

So does this mean your weight is essentially predetermined? Absolutely not. Sure, if you're genetically susceptible to obesity and your idea of a workout is lifting the lid off a bucket of Kentucky Fried Chicken, you will likely be heavier than a fellow couch potato/KFC fiend who has a propensity to be lean. But if you take up cycling and switch from fried chicken drumsticks to skinless baked breasts, you're likely to stay at a healthy weight regardless of your genes. "Someone who has a susceptibility toward obesity just has to be more careful," says Tracy Nelson, Ph.D., M.P.H., an obesity expert at the University of Colorado who has conducted research on twins.

Question #38: Will I burn more calories exercising in hot or cold weather?

The short answer: You burn about the same number of calories regardless of the weather, unless you're so cold that you start to shiver.

Shivering is an involuntary clenching of muscles; its purpose is to generate heat and warm you up. When your teeth are chattering and every muscle in your body is tight and tense, you burn nearly four times more calories than usual. And when it's so cold that in addition to shivering, you have to hop from foot to foot and rub your hands together to keep warm, you burn up to 400 additional calories per hour.

But this isn't a good reason to go out jogging in January in North Dakota wearing nothing but shorts and a tank top. Sure, you'll burn more calories than if you work out properly clothed or indoors on the treadmill, but you'll also risk hypothermia and frostbite.

You don't burn any extra calories by sweating it up on one of those yoga classes where they crank the temperature to 100 degrees, either. It may seem like you're melting away pounds more quickly, but in reality you're just shedding more water than usual. As soon as you take a drink, you replace the water weight. If you don't drink up, you risk dehydration.

Question #82: How do Sumo wrestlers get so fat and how unhealthy are they?

The short answer: Sumo wrestlers get fat the same way other people do - by eating enormous portions of high-calorie fare. The life expectancy of a Sumo wrestler is less than 60 years, far lower than the Japanese-male average of 80 years. Many are plagued with weight-related problems such as difficulty walking, osteoarthritis, and high blood pressure. However, in spite of their belt-popping girth, Sumo wrestlers are healthier than you might expect.

Top Sumo wrestlers are among some of the weightiest individuals on earth. On average they tip the scales at 400 pounds - some weigh in at more than 600 pounds - with an average body mass index of 36.5 and body-fat percentage of 30.

By virtually every standard measure, these large men in diapers are considered obese. But they probably aren't as unhealthy as your typical burger-and-fries-addicted couch potato. Studies show elite Sumo wrestlers tend to have normal cholesterol, glucose, and triglyceride levels. As a group, they don't suffer inordinately from heart disease, they rarely develop Type 2 diabetes, and they have relatively modest amounts of fat deep within the abdomen, the type of fat linked to heart disease and other health problems.

Medical experts speculate that Sumo wrestlers enjoy comparatively good health because they exercise. A lot. Although you don't see too many Sumo wrestlers jogging in the park, their training regimen calls for grueling four- or five-hour workouts six or seven days a week. The problem is that when Sumo wrestlers retire, they continue eating the same way they did when they competed and begin to develop lifestyle-related diseases.

Lately there has been growing concern that Sumo competitors have grown too fat. In 1953, the average Sumo stood 5'11" and weighed 317 pounds. Today, the average wrestler is just 3 inches taller but 95 pounds heavier.

Question #90: Can I trust the labels on supermarket foods or the calorie counts listed on chain-restaurant websites?

The short answer: The information coming from national brands is usually, although not always, pretty accurate. However, in spot checks, many food labels from regional brands have been found to vastly underestimate the number of calories and the amount of fat and sugar contained in the product.

Does your favorite energy bar actually contain the 220 calories it claims to on the label? Do those extra-lean burgers you always buy really contain just 2 grams of saturated fat per patty? Those aren't questions we normally ask. Most of us assume that Nutrition Facts labels - required by law on all processed, packaged food products and relied on by millions to make healthy food choices - reflect reality.

Turns out, many of the labels may not. In a test conducted by the Florida Department of Agriculture and Consumer Services laboratory, 75 percent of diet products tested, most of them regional brands, were shown to have erroneous information on their labels. More than 10 percent of all bakery products and candies tested were mislabeled, as were 25 percent of dressings and condiments. Some of the labels were off-the-charts misleading, like a vanilla éclair that claimed to have 2 grams of fat but actually contained 17 grams. An entire line of "sugar-free" baked goods - more than twenty products - from a regional company were found to contain sugar, as many as 16 grams per serving. Caught red-handed, the baker admitted he added sugar to give the chocolate products more flavor and enable the cookie dough to brown better.

So what's a consumer to do? Your best bet is to assume a modest overestimation of calories and fat grams and make your choices accordingly. Keep in mind that labels that "pass" the accuracy test may not be entirely on target. Federal law allows most products a 20 percent variance from the label; in other words, a bagel that claims to contain 200 calories legally can contain 240 calories.