New ways to get sculpted abs or lose 20 pounds seem to appear every day. But finding a fitness or
diet plan that will fit your lifestyle—and actually deliver results—can be a challenge. Discover the facts, scientific backing, and popular opinions on today's biggest workout and weight loss trends with this guide.
Should You Get Rid of Gluten?What's the Deal? Going on a
gluten-free diet. A protein in wheat, barley, and rye can damage the intestines of those with celiac disease, so they must forgo bread, beer, pasta, and many other products containing the seemingly all-pervasive grains.
Though celiac affects only an estimated 1 percent of the population (and milder gluten sensitivity potentially another 9 percent), many folks without the disease have sworn off the g-stuff…and say they feel better.
Who Swears By It: Besides celiac sufferers, those on the
paleo diet are also gluten-free. Some dietitians, strength coaches, and regular folks have also jumped on board.
What the Science Says: In an article in the
Annals of Internal Medicine, authors Antonio Di Sabatino, MD, and Gino Roberto Corazza, MD, both of the University of Pavia, Italy, argue that there is little evidence, as of now, that non-celiac sufferers who still follow a gluten-free diet are having alleviation of symptoms because they've eliminated wheat. Instead, these non-celiacs, the authors say, may be falling prey to food advertising and marketing claims rather than responding to actual sensitivity: "'Sense' should prevail over 'sensibility' to prevent a gluten preoccupation from evolving into the conviction that gluten is toxic for most of the population."
Why You Might Like It: You might feel better, and you'll probably lose weight. But giving up gluten specifically may not be the reason why. "There are so many other variables," says Sandra Carpenter, RD, Senior Program Manager for Weight Management and Nutrition at the University of Pittsburgh Medical Center. "They may say they're eating gluten-free and feel better, but it may also be that they aren't eating so much pizza!" Dieters also become more mindful of what they're eating and tend to give up foods that aren't good in large quantities anyway, gluten or not—stuff like pretzels, chips, bread, and more.
"It may not be the gluten," says Shawn Arent, PhD, associate professor of exercise science at Rutgers University. "It may be the food choices that go along with this that make it seem very effective."
Why You Might Not Like It: Wheat's tough to give up—and gluten's opponents say that's the problem. In The Wheat Belly, William Davis, MD, claims that the grain has been manipulated to improve yields, making it addictive, acting in the body like an opiate.
"Everything we're eating is Franken-food," says Valerie Berkowitz, RD, director of nutrition at the Center for Balanced Health. "It's creating this situation where a lot of times people eliminate wheat, and they may lose 20 pounds in a month, feel reduced acid reflux, sinus congestion, migraines, and more."
Will You Go Nuts for the Paleo Diet?What's the Deal? Eat like a caveman. Paleo proponents suggest that when agriculture started, everything went wrong—10,000 years isn't long enough for our bodies to evolve to deal with the introduction of grains and other industrially-produced foods, and so we've developed "diseases of civilization," including cancer, heart disease, and obesity.
The paleo solution? Cut it all. This diet includes berries, meat, nuts, seeds, and anything else a hunter-gatherer might find. What you'll skip: Bread, corn, and other foods that require industrial farming or processing.
One argument against this logic: Cavemen didn't live that long, and many of the diseases listed above—especially cancer and heart disease—come as a result of old age more so than lifestyle.
"It goes back to the philosophy of basics, and that whole foods are good," Carpenter says. "But if they had lived until they were 80 or 90, maybe they would have had these diseases, too."
Who Swears By It: Among others, CrossFit athletes love the Paleo Diet.
What the Science Says: In a small study of just nine people from 2009, scientists from the University of California, San Francisco School of Medicine saw a reduction in blood pressure and cholesterol, and an increase in glucose tolerance.
Why You Might Like It: You'll be eating lots of whole foods. As with the gluten-free approach, the benefit of this strategy may not be the "paleo" part, but the "not eating garbage" part, says Arent.
"You're removing a lot of energy density in the form of sugars," he says. "You wind up cutting a lot of non-satiating foods. So you lose weight because you've refrained from bad food choices."
Why You Might Not Like It: As with the gluten-free approach, wheat and other carbohydrates can be tough to kick.
If you're ready to go paleo, learn more with
The Paleo Diet for Athletes.
Would Your Diet Be Better Eaten Raw?What's the Deal? Your food should not be processed—or cooked.
For most raw food enthusiasts, this means a vegetarian approach. But for some, like Aajonus Vonderplanitz, author of We Want to Live, it means eating raw meat and milk as well.
What the Science Says: In a 2005 study of 94 men and 107 women, study participants on a raw food diet lowered their total cholesterol and triglyceride counts, but also lowered their HDL ("good") cholesterol and were deficient in Vitamin B-12 (which is found in high concentrations in beef, among other foods).
Why You Might Like It: You'll get lots of vegetable nutrients, and you'll eat more whole foods.
"From a nutritional perspective, if you're doing a raw, vegan diet, it's going to be very nutritious," Carpenter says. Cooking can leech nutrients out of vegetables. "You're going to have a heck of a lot more fiber. That's something the average consumer doesn't get enough of."
The fiber can have another effect: weight loss. The non-soluble nutrient helps keep you full, and with the amount you'll get with raw, you'll stay full.
Why You Might Not Like It: You may miss the aromas and flavors of cooked food on a raw diet, and you may find it difficult to replace your calories--vegetables, especially, are not very calorie-dense.
Besides the potential B-12 deficiency listed above, Berkowitz says a low-fat, meatless diet misses nutrients like arachidonic acid, a polyunsaturated fat that is key for brain development, and choline, a nutrient that may prevent age-related memory loss and may lower cholesterol.
Want to Double Down on Meat and Go Ketogenic?What's the Deal? Make your body think it's starving, even as you're eating.
If you know about the Atkins Diet, you're part of the way there; ketogenic diets are low-carb, high-fat protocols. Because you're not consuming carbohydrate, the body's preferred fuel, you burn fat, as it would if you were starving.
"Your body has to work a lot harder to get energy out of [protein and fat]," Carpenter says. In a sense, your body is "wasting energy just getting to the energy. And that's why you lose weight."
What the Science Says: Ketogenic diets have been studied for almost 100 years, and are prescribed medically for the reduction of seizures in epilepsy patients.
Among non-epileptics, the diet has been shown to reduce weight many time. Just this year, an Italian study of eight gymnasts found that after 30 days on such a diet, they'd lost an average of 3.5 pounds while reducing their body fat percentage.
Why You Might Like It: For the same reason many people liked the Atkins diet at the height of its popularity--you can eat steak, chicken, butter, and all kinds of fatty stuff, and you'll still lose weight.
"I like ketogenic diets because they're corrective. For so many years people may have eating frozen and packaged foods," says Berkowitz. With a ketogenic diet, you're eating lots of whole foods, non-starchy vegetables, and meats. "What you're cutting out is bread. And bread isn't a food group."
Why You Might Not Like It: As with some of the other diets listed above, you can't eat many carbs, and you may miss them. On many ketogenic protocols, you can, despite popular belief, eat fruit--up to 50 grams of carbs per day from berries and the like.
Your partner (or potential partners) may not like your keto diet: Side effects include constipation, bad breath, and irritability. As such, it's a tough regimen to stick to for an extended period.
Can You Count on Weight Watchers' Points for Results?What's the Deal? Portion control. Whether or not you choose to attend meetings, the points system is designed to help you assign values to foods control how much you eat.
"The program helps people knowledge-build and become more familiar with portion sizes and calories—they may not have paid attention to that before," Carpenter says. "People who have been weight-conscious their whole lives built this knowledge over time."
What the Science Says: A study of 772 men and women published earlier this year in the journal Lancet found that people on Weight Watchers stuck to their diet and lost more weight over the course of a year compared to dieters who received advice at regular doctor's visits.
Why You Might Like It: You can eat just about anything, as long as you stay within your point totals. And meetings can provide much-needed support and camaraderie.
Why You Might Not Like It: You can eat anything, and your cravings may make you squander your points.
"You can lose weight [on Weight Watchers] and not have a healthy diet," Carpenter says. "If someone chooses to use all their points on brownies, they can be within their calorie range and not be getting enough nutrients." This can leave you hungry, she says--your body wants food not just for energy, but for important nutrients.
And if you eat pre-packaged WW meals, you may also be loading up on preservatives, Berkowitz warns.
"Their food has as much crap in it as anyone's," she says. "And from a 'getting-to-better-health' kind of business, do you really want that?"
Are Routine, Intermittent Fasts Right for You?What's the Deal? Contrary to the current conventional wisdom that your body requires tiny meals all day to "stoke the metabolism," proponents of intermittent fasting go long periods without eating in the sake of getting lean. Fasts last six, eight, 10, 16, or even 24 hours.
In one popular version called Lean Gains, dieters eat all of their calories in one eight-hour period, bookending them around their workout.
What the Science Says: Severe caloric restriction, including fasting, has long been known to oppose the development of age-related diseases and changes; one study from Illinois reported this as far back as 1988.
In one study, female rats that underwent intermittent fasting regimens "ceased [menstrual] cycling, underwent endocrine masculinization," and "exhibited a heightened stress response." So, ladies, consult your doctor before trying this regimen.
As for the six meals a day, there aren't any compelling studies advocating this strategy.
Why You Might Like It: If you're busy, and have trouble finding time to squeeze in all those tiny meals, you might like doing a lot of eating at once. You also get to eat some big meals. Participants in Lean Gains, for example, eat half of their day's calories in their post-workout meal.
The results are also compelling. You'll see lots of pictures of smiling, ripped advocates of IF.
Why You Might Not Like It: If you're used to eating a lot of small meals--or if you like it--you may wind up concentrating on your rumbling belly for 16 hours.
"People really have to be true to themselves," says Berkowitz. "If you're going to be thinking about food throughout the day, and you can't concentrate, it may not be for you."
Carpenter says that for some dieters, blood sugar dips and spikes may cause variance in concentration during the fast.
"Depending on the length of the fast, your body can learn to adjust to that to some point," she says. "Your blood sugar will fluctuate based on your activity level. Getting through those first 24 to 48 hours can be a real challenge."
Is Starting Strength Really Right for EVERYONE?What's the Deal? Starting Strength: Basic Barbell Training, by Mark Rippletoe, is a fitness book in its third edition that explains, in great detail, how to perform and deploy basic barbell exercises such as squats, deadlifts, bench presses, overhead presses, cleans, and snatches.
The book is almost universally beloved, and has become almost sacred in certain online circles. On Reddit's fitness forum of more than 200,000, it's recommended by just about everyone to just about anyone.
"For a beginner, someone who has never learned these movements, it's outstanding. The instruction it provides is really, really good," says Arent.
What the Science Says: Barbells make you strong. In a study published in the Journal of Strength and Conditioning Research from May 2012, men who trained for six weeks with a barbell gained more overall strength in the back squat than did a group training with kettlebells. It should be noted that the barbell group used more weight than the kettlebell group, which, naturally, should lead to increased strength.
Why You Might Like It: The instruction is fantastic for beginners. And if you want to get strong, you want to use big weight--and barbells are the easiest way to use maximum load in an exercise.
"You have to ask, what is this piece of equipment superior for?" says Mike Wunsch, performance director at Results Fitness in Santa Clarita, CA. "Most of the guys who start on Starting Strength are looking to have strong lifts in the [deadlift, squat, and bench press]. Barbells are superior for that. For the goal of adding strength and size and mass, it's tough to beat a barbell."
But some strength experts, including Wunsch, think that even with this instruction, it's better to start with bodyweight versions of these exercises.
"You've got to earn the barbell. You've got to master your bodyweight first," he says. "Most guys, they start doing stuff with a barbell, and they can't do one single-leg squat."
Jeremy Frisch, owner and director of Achieve Performance Training in Clinton, MA, has his athletes earn the bar through hundreds of bodyweight repetitions.
"I try to build the biggest foundation I can of movement skill. The movement has to become ingrained in you," he says. After hundreds of reps performed correctly, his young athletes are less likely to be injured when under load. "Once we've got it ingrained in this way, it's much easier to teach the bar. We have a bigger foundation to stand on. And because you do all those reps, you get a training effect from that."
Why You Might Not Like It: While it's an excellent manual, if your goals aren't just strength and size, you may need more.
"Barbells are great for overhead pressing and squatting, but they're not the end-all, be-all for every movement," Wunsch says.
For those most interested in losing fat, for instance, other workouts like interval cardio and higher-volume weight training will push users closer to their goal, Arent says.
"If people have joint injuries, they may need to work with someone who can adapt these exercises to them as well," he says.
Is CrossFit Worth the Hype?What's the Deal? CrossFit offers a different high-intensity workout every day. It's built an enormous, intense following of trainees who like its daily variation, high intensity, and short workouts. Many of the shirt-soaking sessions take just 10 minutes.
Such routines may consist of sprints, Olympic lifts, bodyweight exercises, plyometrics, or a combination thereof. The company is selling the idea of a fitness generalist who is proficient across 10 general skills: cardiovascular and respiratory endurance, stamina, strength, flexibility, power, coordination, agility, balance, and accuracy.
What The Science Says: In a 2010 study by the US Army, 14 athletes were put on a CrossFit program for six weeks, performing at least four workouts of one hour each per week. There was no control group, but these 14 experienced an average increase in power output of 20 percent after eight weeks. Work capacity among this group increased by 14 percent.
Why You Might Like It: It's a fast-paced, team atmosphere, where other participants cheer you on as you work to complete the day's workout. There's plenty of variety, and perhaps best of all, you don't have to think about what you'll do that day—the workout is posted on a whiteboard.
Why You Might Not Like It: Because the workouts vary so much and so often, it's hard to gauge your progression, says Arent. (Many Crossfit gyms, however, do not simply follow the daily workout of the day posted on CrossFit.com, repeating workouts periodically so visitors can track their progress over time.)
If your goal is specific—not to be a fitness generalist, but to improve in a specific area—the daily workouts aren't designed for you.
Finally, you may not like the price tag. Unlimited access to these gyms can cost as much as $250 per month, and even limited access can cost $135 per month or more.
Photo Credit: Courtesy of Reebok CrossFit