BY THE TIME 32-YEAR-OLD Amy Claflin checked herself into Utah's Green Valley Spa last summer, she was starting to think she would never shed the 20-pound legacy of her fourth pregnancy. She had tried cutting out sugar, eating less fat, skipping meals, even living on Slim Fast drinks, but nothing seemed to work as advertised. Now she thinks she knows why. At Green Valley, she got a "body type evaluation." After assessing her shape, stature and food preferences, a counselor declared that she had a "gonad-al" style of metabolism and proposed a diet designed just for people like her. Claflin was told to avoid the rich, spicy foods she craved and stick to fish, chicken and light dairy products, plus plenty of fruit. Thanks to her new diet and an exercise regimen, she lost 22 pounds and migrated from a size 10 dress to a size 5. "It's the easiest plan I've ever tried," she says.
It may sound like Claflin simply started taking care of herself, but some nutritionists insist she did more than that. Forget the carbo cult and the more recent protein craze. Proponents of several new specialty diets claim that the nutritional effect of any given food depends on your ancestry, blood type and metabolic rate. And they maintain that the key to staying slim, energetic and healthy is to eat according to your needs-even if that means forsaking brown rice for cheese steak. "There is no one diet that works for everyone," says nutritionist Ann Louise Gittleman, author of "Your Body Knows Best" (226 pages. Pocket Books. $6.50). "The answer is to figure out what you need for your inherited tendencies." She may be on to something, but beware of programs promising to pinpoint your ideal eating plan. Most of them make palm reading look like serious science.
The Green Valley Spa's program is based on the work of Elliot Abravanel, a Beverly Hills physician. Building on earlier speculations by nutritionist Henry Bieler, Abravanel decided back in the '80s that there are four types of people, and that their cravings depend on which glands dominate their metabolism. Without directly monitoring the behavior of any gland, he surmised that people with "dominant" thyroids love sweets and starches, while those with overbearing adrenal glands crave meat and salt. Pituitary types go for dairy products, he says, and people with supercharged gonads crave anything fat 'n' spicy.
According to Abravanel, those preferences set us all up for obesity. By giving in to our cravings, he says, we overstimulate our dominant glands. As the glands start to flag, we react like junkies, consuming more of our "downfall foods" just to get the same hormonal high. To keep people out of this alleged cycle, Abravanel prescribes gland-specific diets-more lean protein for thyroid types, more carbs for adrenal types and so on. He claims that people who follow his plan stay slender and healthy, and deal better with the normal stresses of life.
Peter D'Adamo is on to the same general idea, but he has a different prescription. In a hot-selling new book called "Eat Right 4 Your Type" (392 pages. Putnam. $22.95), the Connecticut-based naturopath says that eating what you like can be good for you. In a speculative leap, he argues that the four major blood groups-O, A, B and AB--evolved in different natural settings and predispose people to different styles of life. Type O, the oldest and most prevalent of the four types, is the blood of the hunter, according to D'Adamo. It demands red meat and hard-core exercise. A is supposedly the agrarian blood type. It emerged in the Middle East or Asia, not long before the advent of farming. And because type-A carriers have low levels of the stomach acid needed to break down fatty meat, D'Adamo figures they're adapted to plant-based diets. Type B is newer still, and supposedly a balance between O and A.
Gittleman's program draws on D'Adamo's but includes other elements as well. She says she has seen "many, many people" become flabby and malnourished while following the mainstream edict to eat complex carbohydrates and avoid animal fat. To put them back on track, she considers not only their blood types and ancestries but their so-called oxidation rates. People who burn fuel slowly tend to store their excess carbs as fat, she says, while "fast burners" go through them so quickly that they're always hungry. So she advises both groups to cut back on bread. cereal and fruit and eat more protein. She concedes, though, that her "revolutionary eating plan" is based mainly on her experience, not on rigorous clinical study.
No one denies that people have individual needs. George Bush and Shaquille O'Neal are both vigorous fellows, but no nutritionist would put them on the same meal plan. And there's no question that what's good for one person can sometimes harm another. Dr. Victor Herbert of New York's Mount Sinai Medical College notes that supplements of iron and vitamin C, while immensely helpful to people prone to iron deficiency, can devastate those prone to overload. Even so, most experts scoff at the notion that there's no such thing as a universally healthful diet. The rise of obesity and chronic illness is no great mystery, says Dr. Boyd Eaton, an Atlanta radiologist who has published numerous studies on evolution and diet. We all tend to eat far more fat, salt and sugar than our hunter-gatherer ancestors. We've replaced nutrient-rich plant foods with processed cereal grains. And we get only a fraction of the vigorous exercise that filled even our grandparents' days. "To say that some people can eat a lot more fat than others begs the issue," he says.
Proponents of the new diets all have stories about people who fared better on their plans than on conventional low-fat fare. But until someone publishes hard data on the effect of eating for your blood or body type, there's no reason to swallow any of the new prescriptions. "Someday we may know how to tailor a diet to an individual's genetic makeup," says Bonnie Liebman, a nutritionist with the Center for Science in the Public Interest, "but we're not even close." Dr. Dean Ornish, a San Francisco cardiologist famed for his diet-based assault on heart disease, notes that thousands of studies have confirmed the benefits of a low-fat, plant-based diet. "Telling people that they should eat more meat because they have type-O blood is irresponsible," he says. Maybe so, but it sure sells books.
GIVE THEM RED MEAT AND PLENTY OF IT! Ancestry: If your forebears lived in northern climes, say the niche-diet gums, don't skimp on red meat and other foods rich in fat and protein. They were your ancestral mainstays.
Blood type: Proponents of one theory say people with type-O blood have evolved to live like hunters. For optimum health, they need intense physical exercise and plenty of animal protein. High levels of stomach acid help them dissolve it.
Metabolism: Some nutritionists say people with rapid metabolisms need slow-burning red meat to keep their energy up. A carnivorous diet is said to prevent weight gain by warding off frequent food cravings.
CARBO-LOADERS GO WITH THE GRAIN Ancestry: People who hail from temperate farming areas are said to thrive on grain-based diets that would leave a natural carnivore flabby and listless.
Blood type: Some say blood types A and AB emerged recently, as adaptations to agriculture. Pop theory holds that people with these blood types are uniquely suited to high-carb diets.
Metabolism: Some nutritionists say carbo-loading is only for athletic people with efficient body furnaces; carbohydrates can cause obesity in "slow burners" (by stimulating insulin production) or "fast burners" (by leaving them constantly hungry).
FOR FAT STORERS, LEAN AND MEAN PROTEIN Ancestry: Fish and fowl offer animal protein without the fat content of red meat. Some say they're perfect for people from Asia or southern Europe, where diets have long been more varied and less meat-based.
Blood type: People with type-B blood are supposedly less meat-dependent than people with type-O blood, but not genetically equipped to veg out completely.
Metabolism: According to one model, people with slow metabolism should get their protein from chicken and fish. They're ill equipped to burn all the fat in red meat, so they store it under their skin.