If you've visited a bookstore this month, you probably weren't able to avoid the giant pyramid of diet books that magically appears right after Jan. 1. Whether you find those titles inspiring or just guilt inducing, one thing is certain: many of them sound too good to be true. And often they are. These popular weight-loss fads usually aren't all that new, but they come around every year with new names—and maybe even a fresh celebrity connection. Here are the six basic diet trends, why they don't work and why they may even be unhealthy. You won't find these exact titles on a shelf near you, but hopefully you'll be able to recognize the gimmick when you see it no matter how it's been tarted up.
(For more on weight loss, check out this story about diet tactics that are backed by science: "What Works.")
1. The Fat-Free Diet
The theory: Eat whatever you want as long as it has no fat. If your diet contains no fat, you won't get fat.
Reality check: While it's true that extra fat in your diet adds calories, just sticking to foods touted as fat free doesn't necessarily help. Supermarket shelves are crammed with products advertised as fat free that are loaded with sugar and empty calories and that offer little in the way of fiber, vitamins or minerals. Check product labels before you buy.
2. The Snack-Pack Diet
The theory: Cookies and chips sorted into 100-calorie packs help limit the damage from an attack of the munchies.
Reality check: The dozens of 100-calorie snack pack foods on the market now may offer a lower-calorie alternative, but few of them are truly healthy choices, and they aren't likely to be very filling or fiber rich, which can send you running for another bag or something less healthy. Rather than knocking back a 100-calorie bag of Cheetos or Oreos, look for more nutritious alternatives, like half of a sandwich made with whole-wheat bread or a piece of fruit.
3. The Couch-Potato Diet
The theory: Who needs exercise? You can lose weight without working out! Cutting back on calories is enough.
Reality check: Who needs exercise? You do. Studies have shown that dieters who change what they eat and increase their regular activity are more likely to lose and keep weight off. Increasing activity has other health benefits as well, such as lowering your risk of heart disease, the leading killer of women. Even a brisk 20- to 30-minute walk most days of the week can make a big difference.
4. The Detox Plan
The theory: You'll lose weight when you clean out your insides by downing a concoction made from orange juice and molasses or some other bizarre mix.
Reality check: There's no evidence that purging your intestines of "toxins" makes you any healthier or more likely to lose weight. A high-fiber diet is all you really need.
5 . The Beef and Bacon Diet
The theory: All protein, all the time, and don't worry too much about fat.
Reality check: Cutting down on carbs, especially empty carbs like white flour and white rice, can help you lose weight, but a diet that contains large amounts of fatty meat simply isn't healthy. A better choice would be leaner proteins, like fish or chicken (grilled or broiled without the skin), plus five servings of fruit and vegetables, a serving or two of whole-grain carbs and some low-fat dairy.
6. The Twinkie Diet
The theory: Calories are all that counts, so eat whatever you want, including nothing but Twinkies, and you will lose weight as long as your total is under your daily limit.
Reality check: Although calories do count, the source of those calories is important. If you eat only junk, your body will lose out on vital nutrients and that can have long-term consequences for your health. So watch those calories, and watch where they come from.
So instead of spending $25 on another book advocating one of the above approaches, try going back to basics.
The first, admittedly obvious, step is to eat less. You may not even be aware of how much or what you are eating. Keep a food journal for a few days. It will help pinpoint trouble spots. Studies have shown that writing down what you eat is one of the most effective ways to cut back and that dieters who do so tend to lose more weight than those who don't. One of the most helpful books out there on the psychology of why we eat is "Mindless Eating" (Bantam Dell) by Brian Wansink, head of the Cornell University Food and Brand Lab. In addition to explaining the many reasons it's so easy to overeat in American culture, he offers tips that can help you reduce consumption more easily, like buying smaller plates or even just moving the candy dish a few feet farther from your desk.
The second step is also pretty simple: get more exercise. One upside of the current economic downturn is that lots of gyms are offering discounts on membership. Take advantage of that.
For more diet and exercise tips, check out mypyramid.gov. It's a free government site with easy-to-use diet and exercise trackers.