You’ve heard about diets that are geared towards everything from your blood type to your astrological sign. The latest pound-shedding plan—“The Hunter/Farmer Diet Solution: Do You Have the Metabolism of a Hunter or a Farmer? Find Out…and Achieve Your Health and Weight-Loss Goals” by Mark Liponis, M.D., the corporate medical director of Canyon Ranch—is based on your metabolism and where you tend to gain weight. Intriguing, right?MORE: Battle Mid-Life Weight GainHere’s the scoop: People who tend to put on belly fat fall into the “Hunter” category, while those who are more likely to pack on pounds around the hips and thighs are “Farmers.” The book recommends dietary changes for each (one group should focus more on carbs and the other on proteins—can you guess which?). But first, you need to figure out which type you are.The simplest way to determine that is by birth weight: those with a birth weight of less than seven pounds tend to be Hunters, while seven to 10 pounders tend to be Farmers. (No word on scarily large newborns, but let’s go ahead and hope for mothers everywhere that they’re rare!) To find out the other determining factors and which category you fall into, take this quiz.“Most diets are trying to get people to eat the same way, but few help people to pick the right one for them,” says Dr. Liponis, explaining what differentiates his plan from the sea of fad diets constantly marketed to the public. “This diet is based on nutrigenomics, which is the idea that genes can help us determine the best way to eat. And people do need different ways to eat; it’s not one size fits all.”MORE: 10 Confusing Eating Conundrums—SolvedEssentially, the idea is that these two body types represent genetic and hormonal differences in how people metabolize carbohydrates and fats. Liponis also thinks that in following the diet, people can help reduce their risk for disease. He maintains that Hunters tend to develop diabetes and cardiovascular disease, while Farmers may be more susceptible to cancer and Alzheimer’s.So here’s the nitty-gritty: According to the book’s premise, Farmers are more sensitive to insulin and efficient at absorbing glucose, so they should eat frequent small meals and snacks. They’re instructed to stick to a high-carbohydrate, low-fat diet (including whole grains, bread and pasta) and to “exercise first thing in the morning after breakfast,” says Liponis. Hunters are encouraged to follow a low-glycemic diet that emphasizes meat, fish, eggs and low-carb vegetables (think salmon, grass-fed beef and free-range poultry), do aerobic activity before dinner and “take a walk after.”Liponis says that his theory is based on research and findings derived from Stanford University’s famous A to Z weight loss study. Published in the March 7, 2007 issue of the Journal of the American Medical Association, the research compared the weight loss success of 300 women randomly assigned to various diets that ranged from low-to-high carb intake. They then compared the relative success of each diet based on weight loss. The four major diets (prepare yourself for a blast from the past) were: Atkins (very low carbohydrates), the Zone (low-carb, high protein), the LEARN Program for Weight Management (high carb/moderate-low fat) and the Ornish diet (very low fat).MORE: Are Low-Fat Diets Making You Fat?Each group charted weight loss, but Liponis says he was most intrigued by the results of the Atkins group, who lost more weight than anyone overall. However, “some of the women in the Atkins group lost weight, but some gained,” he says, explaining that this made him suspect there was a genetic, metabolic reason at play. “High protein can be good for a Hunter who’s fasting triglycerides are above 150, which shows pre-diabetic insulin resistance, but not necessarily for a Farmer type that is below 150.”With this in mind, he developed the idea further by linking these characteristics with the two ways people tend gain weight—around the stomach area or around the hip and leg areas. So what if you’re a bit of both? “You can have weight gain all-around, but most people tend toward one or the other,” he contends. For the record, he says more women tend to be Farmers, which he thinks has something to do with estrogen, while the majority of men are Hunters, perhaps owing to higher levels of the stress hormone cortisol, which has been linked to weight gain in the midsection.Sure, in theory, this makes sense, but the diet begs a few questions. For example, what in the world does birth weight have to do with any of this? “Low birth weight babies are more likely to become diabetic adults; the stress of their birth programs them for insulin resistance and diabetes,” Liponis explains. “Small babies were more stressed in the womb, and they are born better adapted to stress and prepared to enter a world where food may be scarce. Hunter types are better adapted to deal with food shortages.”MORE: Why You Crave Comfort FoodStill, some in the nutrition community question the validity of Liponis’ claims. For example, some of the rules are controversial, such as making it optional for Hunters to eat breakfast and indulging in ice cream over sorbet because of its ratio of fat, protein and sugar, and most especially, for asking followers of the diet to identify themselves as being in one category or the other. “This immediately causes issues because many people fall into both categories, and the diet does not provide guidelines for these ‘hybrids,” says Karen Congro, R.D., director of the Wellness for Life Program at The Brooklyn Hospital Center. “In many ways, this is more of a philosophy than a diet.” (Liponis is quick to admit that people aren’t always going to fall to opposite sides of the scale—there are plenty in the middle with a slighter tendency one way or another—but again, maintains that they tend toward one or the other.)More importantly, Congro worries about the practicality. “While many of the recipes in the book look delicious, they are not quick and easy,” she says. “Some use unusual and expensive ingredients, such as fish stock and veal demi-glace.” Also crucial, she points out, is that “the diet says that Hunters can skip breakfast. But people who are on medication should never skip breakfast.”MORE: Slim Down With These Three Filling BreakfastsThe bottom line: We’re big fans of eating plans that encourage consuming healthy foods such as whole grains, lean proteins and vegetables, but it’s hard to call this diet scientifically conclusive. For now, we’ll take the Hunter-Farmer diet with a grain of (healthy Celtic Sea) salt.