- Nutrition -

Delving into Diets

They’re hard to follow and easy to hate. Research suggests that most diets backfire in the long run, and some can even be hazardous to your health. Yet for some people, diets deliver decent results. So what gives? We explore what really makes diets effective when they do work — and what’s to blame when they don’t.

Go ahead, pick a diet. Any diet. Atkins, Ornish, Caveman, South Beach, SugarBusters, Hamptons, Martha’s Vineyard, Zone, Mediterranean, Fat Flush, Blood Type. All these diets have a huge popular appeal. Described in hopeful, gung-ho language, each new diet book promises amazing results. For some folks, these diets work. For others, they fail. But on the whole, for as much as we might swear we hate dieting, a whole lot of us appear to be eating it up.

According to the American Institute for Cancer Research, as many as 40 percent of American women and nearly a quarter of American men are on some kind of weight-loss diet at any given time. Check out these numbers:

  • Last year, Americans spent more than $15 billion on low-carbohydrate products, prepared meals, books and services – an industry launched by the late diet guru Robert Atkins, MD.
  • More than 44,000 Weight Watchers meetings are held worldwide every month.
  • The South Beach Diet, by Arthur Agatston, MD, has sold more than 8 million copies since its publication in 2002.

While many of the most popular and reputable weight-loss books (including The South Beach Diet and The Fat Flush Plan) make it clear that they are proposing lifelong eating strategies, not just get-thin-quick schemes, the fact is, many people who undertake such plans do it in hopes of losing some weight and then taking a “we’ll see” attitude. Unfortunately, it’s a rare person who starts a weight-loss plan fully intending to change the way he or she eats for a lifetime. And even the best intentions often go awry.

It’s for this reason that many doctors (particularly the ones who haven’t yet written a diet book of their own) decry the whole concept of dieting as shortsighted and ill-advised. The very term “diet,” they say, suggests a temporary and unsustainable departure from one’s regular eating habits. And, of course, people who take pounds off while “on a diet” almost invariably put them back on (and then some) once they’ve gone back to their old ways. Which is usually just a matter of time.

It’s for these reasons, and more, that most nutritional experts see diets as quick fixes whose long-term prospects are limited. They’re particularly concerned about diets (like the first phases of Atkins) that depend on guidelines that reduce nutritional variety and balance in ways that jeopardize health. They also frown on any diet that might have an unintended, undermining effect on normal energy metabolism.

The American College of Preventive Medicine, for example, recently issued a position statement roundly condemning many popular weight-loss plans. “Fad diets generally emphasize short-term weight loss while neglecting considerations of long-term health, and are to be discouraged,” the authors stated.

These pros would prefer to see you lose excess weight by simply eating a bit less, a bit healthier, and by exercising a bit more. But, unlike the famous diet docs, they won’t tell you precisely what to eat, or when to eat it. They don’t really differentiate between Atkins, Ornish and Cabbage Soup. And while they’ll caution you that cutting too far back on specific foods or entire food groups can lead to shortages of essential nutrients your body needs for health, their suggestions (predictably, to eat a sensible, well-balanced diet in keeping with your body’s daily nutritional and energy needs) are vague enough that they leave average folks clueless about where to begin.

These experts are also ignoring one important fact: For millions of people, popular diets do actually work. Which is to say, they work better than whatever these people happened to be doing before. And in some cases, what began as a diet turns into a healthier way of eating for a lifetime. The result? People take the weight off and keep it off. They get healthier and more vibrant. They suddenly find they have the energy to begin exercising more vigorously. So is it magic? Miracle diet voodoo? Hardly.

Playing to Lose

In 2004, Michael Dansinger, MD, of Tufts University, released the results of a study of four diets: the Zone diet, Atkins, Weight Watchers and the Ornish (low-fat, mostly vegetarian) diet. After a year, study subjects following these brand-name diets had lost significant (and similar) amounts of weight. Those following Atkins had dropped 3.9 percent of their starting body weight; the low-fat Ornish plan, 6.2 percent; Weight Watchers, 4.5 percent; and the Zone, 4.6 percent.

The fact that disparate, even warring, diet plans can be equally effective for weight loss raises an interesting question: Why is it that all these different eating plans work and, moreover, appear to work about the same?

It may not be for the well-advertised, magic-bullet reasons that dieters assume. The first reason, for example, is shockingly simple: They’re low-calorie. When the American Institute for Cancer Research did a detailed analysis of the specific portion recommendations in four successful diet books, including Dr. Atkins’ New Diet Revolution, they found that the result was a calorie total low enough to guarantee weight loss.

The other thing is, if you read the fine print, many of these diets are not as faddish, or as innovative, as they may first appear. In fact, different as they may seem at first, these diets (particularly in their maintenance phases) have quite a lot in common. Under all the marketing hype, many of the ? leading brand-name diets promote the same collection of fundamental principles that have long been known to encourage weight loss and healthy weight management.

This is important, because while the merits of “dieting” may be hotly debated, it seems likely that for many habitually unhealthy eaters, following any reasonably designed, moderate diet – even if only for a while – may prove useful. It might help them learn some nutrition fundamentals, for example, and allow them to realize that they feel better when they’re eating healthier. It might also help them gain some healthy shopping, cooking and eating skills they can apply long after they’ve left the official “diet” behind.

It turns out that as long as you’re good at reading between the lines, it probably doesn’t really matter if you follow any particular diet right down to the letter.

By emphasizing the best of the underlying nutritional and weight-control concepts of popular, brand-name diets (without getting caught up in their fuss and nonsense, or going into a yo-yo spin cycle) you can customize and adapt virtually any plan so that it works for years, even a lifetime. Which, of course, is the whole idea. “It’s the people who understand the principles who do well long term,” acknowledges Arthur Agatston, the author of The South Beach Diet.

So, whether you’re following a diet, are considering one or have forever sworn against them, it’s worth knowing the concepts and real-life practices that are responsible for making most diets work, when they do. If you want to enjoy a healthy, sustainable weight without enduring the rigors of endless diet hopping, start right here – with the fundamentals.

Eat a Healthy Balanced Diet

Remember the grapefruit diet, which restricted dieters to three grapefruit a day? The banana diet? Cabbage soup diet? Diet critics frequently cite such extreme regimens when they caution that trendy diets encourage unbalanced eating by promoting overconsumption of some foods and declaring certain foods, and even whole food groups, off-limits. And wisely so.

But it’s important to note that the average American diet is rather unbalanced to begin with: heavy on animal foods, processed carbs and sweets, and skimpy on fresh fruits, vegetables, legumes and whole grains. Such a diet is likely to result in major weight-control (and health) problems.

By contrast, the more thoughtfully designed popular weight-loss plans – including South Beach, Mediterranean, Fat Flush, even Atkins (if you actually read the whole plan, not just the “unlimited bacon and hamburgers” part) – actively encourage dieters to consume a variety of fresh, natural plant foods, and a reasonable balance of protein, carbs and fats. They thereby support, if not a perfectly balanced diet, then at least a diet considerably more balanced than many careless eaters were consuming before (see No. 3). The result: Once on the diet, people experience a better-functioning body that’s less resistant to shedding excess weight.

Healthy nutritional balance can encourage weight loss in several ways, says James LaValle, a pharmacist and naturopathic physician based in Cincinnati and author of Cracking the Metabolic Code (Basic Health Publications, 2003). For example, an underactive thyroid gland is a common cause of slow metabolism and, consequently, weight gain. Among the many factors that can lower thyroid function are high levels of adrenal stress hormones such as cortisol, and LaValle points out, “Eating a lot of sugar triggers the release of adrenal hormones.” The average American diet is 18 percent sugar. The average popular diet is most certainly not!

Another example is fiber. The American Dietetic Association recommends a daily fiber intake level of 20 to 35 grams per day. The average American diet is woefully deficient in fiber, containing only 14 to 15 grams per day. According to LaValle, “Fiber increases the sensation of fullness, helping to reduce appetite.” Indeed, studies have shown that those who eat the most fiber are much less likely than the average person to be overweight. By incorporating more whole foods and roughage from fruits and vegetables, most popular diets end up increasing daily fiber intake.

Eat When You Need Energy

A spate of recent research has shown that, in terms of weight control, when we eat is almost as important as what we eat. “We’ve learned that it’s essential to coordinate energy intake with energy expenditure,” says John Ivy, PhD, coauthor of Nutrient Timing (Basic Health Publications, 2004). “Calories are put to their best possible use when they’re consumed at times when there is a strong demand for them in the body.”

Morning is a time of relatively high caloric demand because the body has gone eight to 12 hours without any nutrition. Calories consumed in the morning, when we are active, are more likely to be used for energy during the course of the day, as opposed to being stored as fat during the more sedentary evening hours. Meeting the body’s morning caloric needs by eating breakfast has also been shown to reduce caloric intake later in the day. Finally, eating breakfast may also boost your activity levels by boosting your energy.

The net result is fewer total calories consumed and more total calories burned over the course of the entire day. In fact, a study from the University of Massachusetts found that those who regularly skip breakfast are 4.5 times more likely to be overweight than those who eat it most mornings.

Eating smaller meals more frequently (five or six times a day) is another proven way to better coordinate food intake with energy needs. A study published in the British Medical Journal (Dec. 2001) found that those who ate most frequently were thinner and had lower cholesterol and triglyceride levels than those who ate most infrequently. As with eating breakfast, the reason seems to be that more frequent eating reduces appetite and increases activity levels.

Most popular diets prescribe eating plans that include breakfast and smaller meals and snacks eaten more frequently throughout the day. The South Beach Diet, for example, recommends spreading your total food intake over six small meals per day. Thanks to its positive impact on metabolism, a healthier eating schedule (including the introduction of a good breakfast) could very well result in weight loss – other dietary changes notwithstanding.

Watch What You Eat

One of the most fundamental aspects of any diet is the act of monitoring what you eat. And for many, just having that consciousness (as opposed to eating mindlessly) is an effective tool for reducing caloric intake.

In fact, research shows that simply paying attention to what you eat is one of the more effective ways to cut the amount of food you consume. Self-monitoring strategies are a key habit among members of the National Weight Control Registry (NWCR), a research pool comprising several thousand men and women who have lost an average of 66 pounds apiece and kept the weight off an average of six years. “They’re very conscious of their eating,” says Suzanne Phelan, PhD, a spokesperson for the NWCR. After six years, she notes, “about half of them report that they are still counting calories and fat grams.”

But you don’t necessarily have to calculate calories or grams of anything in order to benefit from a more conscious and “planful” style of eating. By starting the day with some sense of what you will consume for various meals and snacks, then either sticking with that presumably reasonable plan or consciously noting and correcting where you veered off course, you stand to gain much of what many diets have to offer.

Avoid the Bad Stuff

Just about every popular diet has a “forbidden foods” list. The specific foods and food types differ from one program to the next, and it is the forbidden foods that earn many diets their fame: The Atkins diet forbids virtually all high-carbohydrate foods. The Ornish diet forbids most animal foods. Peter D’Adamo’s blood-type diet forbids a long laundry list of seemingly unrelated foods for each of the four basic blood types.

While many nutritionists regard such enforced restrictions as unnecessary and extreme, there is something to be said for having an “avoid” list. Because no weight- loss diet – and no healthy-eating plan, for that matter – can succeed without some restriction of the foods that are most responsible for creating large body-fat stores and for undermining physical vitality.

A majority of mainstream nutrition experts agree, for example, that we would all do well to minimize our intake of “bad fats” (trans fats and excessive saturated fats) and “bad carbs” (simple sugars and starches), all of which are heavily represented in many processed and fast foods. Indeed these same sensible restrictions are manifest in most of the better popular diets.

That alone can work to a dieter’s advantage. If the diet you choose restricts the foods in which you tend to indulge (baskets of bread before dinner, or ice cream after every meal, for example), then you’re likely to drop a few pounds just by dropping that temptation, or at least reducing your attachment to it. But the mentality that relegates any food to a “never again” list is far less likely to do you good.

Mainstream nutrition experts warn against taking food restrictions too far. “To totally eliminate specific foods and food groups, especially those that people enjoy, is a recipe for disaster, because it can lead to feelings of deprivation, not to mention nutritional imbalances,” says Elisa Zied, MS, RD, a spokesperson for the American Dietetic Association.

For example, Zied explains, low-carb dieters who go overboard with carbohydrate restriction risk getting too little fiber and not enough vitamin C. “Also,” she adds, “people who exclude or severely limit carbohydrate-rich foods such as fruits, vegetables and whole grains often make up for lost calories by overdoing less nutritious foods rich in protein and fat. Over time, such imbalances can tax the kidneys, cause fluid imbalances and contribute to disease.”

James LaValle prescribes only “soft” restrictions to his clients and to the readers of his many nutritional books. That is, he does not forbid any foods outright, but advises reduced consumption of less healthful foods, such as fried items. “You get gurus who say, ‘You can never eat another dessert again,'” he notes. “That just sets people up for a guilt complex.” The moment folks cheat even a little, he explains, they experience an excessive sense of failure or hopelessness, and this encourages them to abandon their fledgling healthy habits altogether.

It’s worth noting, though, that by generally avoiding junk foods (particularly those that contain lots of artificial flavors and sweeteners) you’ll slowly begin to “reset” your taste buds so that previously “addictive” cravings disappear. Over time, in fact, you’ll probably find that fast food and junk food both lose their appeal (to many healthy eaters, such foods smell bad and may even make them feel ill).

Eat More Whole Foods

The concept of caloric density, or energy density, refers to the number of calories per unit of volume in a given food. A food that packs a lot of calories in a small area is said to have high caloric density. Because water and dietary fiber are basically noncaloric, foods that contain a lot of water or fiber or both tend to have low caloric density. Generally speaking, processed foods are calorically dense, while fruits and vegetables, with their high water and fiber content, are far less dense.

Caloric density is an important concept for those seeking to lose weight, because research has shown that people tend to eat a consistent volume of food regardless of the number of calories it contains. In a Penn State University study, women were fed either a high-density, medium-density or low-density meal three times a day. The subjects chose to eat the same weight of food no matter its caloric density, and when eating the high-density meals, they unknowingly took in 30 percent more calories than when eating the low-density ones.

The lunch entrée, for example, was a pasta bake made from medium shells, zucchini, broccoli, carrots, onions, tomato sauce, and Parmesan, mozzarella and ricotta cheese. The low-density version contained more vegetables, while the higher-density versions contained more shells and cheese.

When popular diets steer dieters away from processed foods and encourage higher intake of fresh plant foods and other whole foods, they naturally improve nutrient balance and decrease caloric density, thus promoting weight loss. But you can employ the same principles without ever going on a diet. Just eat more whole foods, and rebalance your dishes so they represent a less calorie-dense mix.

A bonus: Since whole foods tend to be much higher in nutrients, when you include more of them in your diet your body is likely to become healthier, more energetic and more inclined toward regular activity.

Make a Commitment

Healthy eating is not like a vaccine: one shot and you’re covered for life. Instead it requires a daily, lifelong commitment. There is growing evidence that the more consistent you are in your wholesome eating habits, the greater your chances of maintaining a healthy body weight.

Again, the members of the National Weight Control Registry set an example. “One of our most recent findings is that they do maintain a very consistent eating pattern,” says Phelan. “Unlike many dieters, they tend to eat the same during the week as on the weekends. The same holds for the holidays versus the rest of the year. They tend to have a consistent eating pattern throughout the year.”

Despite their reputation as “fads,” “crazes” or dietary trends, if taken at their word, many of the best-selling diets actually support this kind of consistency – by combining structured eating plans (and often, recipes) with more fundamental principles that are meant to be followed indefinitely.

“People want to be told what to eat and how much to eat every day,” asserts Agatston. But even if you prefer to decide that on your own, developing some consistent rhythm and set of eating principles is one of the best ways to maintain solid results over time.

Make It Matter

The reasons an individual embarks on a weight-loss plan has a profound effect on how well his or her plan is likely to work. “One thing we’ve found is that people who have medical triggers for their weight loss are more successful in the long term than people who don’t,” says Phelan. It seems that when a doctor tells you that unless you lose weight you’ll have a severe heart attack, debilitating diabetes or a stroke, you’re a bit more likely to make a real and lasting change – including starting and sticking with a healthy eating plan.

When you’re authentically motivated, you’re also less likely to lean on lame excuses. Under the scrutiny of research, many common excuses for a diet not working don’t hold up. For example, it is often assumed that successful dieters have more inherent willpower. Yet most members of the NWCR actually failed in several weight-loss initiatives before they finally succeeded, indicating that something about their circumstances rather than their psychological makeup was the key. It’s not uncommon for people who have finally lost weight after multiple tries to explain it this way: “I finally just decided I wanted to start living differently.”

The fact is, each of us is unique – genetically, metabolically, psychologically and circumstantially. For this reason, there’s no single diet plan that works well for everyone. “Each person needs to find what works for him- or herself,” says Zied.

That includes saying no to diets that hold no appeal or don’t serve a real purpose for you. But it also includes saying yes to the underlying principles of healthy nutrition. And if trying (or even sticking with) a reasonably healthy “diet” – brand name or otherwise – helps you do that, more power to you.

So go ahead, pick a diet. Or don’t. If your body likes what it’s getting, you’ll see and feel good results. And if it doesn’t, it’s probably because the way you are eating isn’t characterized by the principles described above.

Consider your own eating habits. Do a little analysis. Once you figure out where you are falling off the healthy-eating wagon, you’ll know precisely how to get back on again. And how to stay there for the long haul.

Matt Fitzgerald is the author, most recently, of the Runner's World Guide to Cross-Training (Rodale, 2004).

Leave a Comment

Subscribe to our Newsletters

Weekly Newsletter
Monthly Newsletter
Special Promotions