How the Volumetrics Diet Works
The Volumetrics diet isn't a diet that will help you lose 10 pounds in a week. Instead, Rolls says that you should aim for something reasonable and sustainable. She suggests a goal of losing 5% to 10% of your current body weight, shedding a pound or two a week.
Some of the key parts of the Volumetrics diet are:
Eating foods with low energy density. Rolls suggest that instead of counting calories you learn what kinds of foods are high and low in calories so you can make better choices. To help you out, The Volumetrics Eating Plan, provides three weeks of complete eating plans for every meal and snack.
Keeping records of the foods you eat and the amount of physical activity you get. Rolls also suggests that you log your weight at least once a week -- and not more than once a day -- to follow your progress.
Increasing your physical activity. You need to start slow, but Rolls suggests that you should eventually aim to exercise for about 30-60 minutes on most days. She says that walking is a great approach for many people and recommends using a pedometer.
Learning how to calculate energy density in foods so that you can eat -- and shop -- more wisely.
What the Experts Say About Volumetrics
To get some expert advice on Volumetrics, WebMD turned to three nutritionists who are all spokespeople for the Academy of Nutrition and Dietetics (formerly the American Dietetic Association). On the whole, they praised the diet's approach.
"It's a slam dunk," says spokeswoman Roberta Anding, MS, RD. "I think it's the best diet out there. I've used the same principles in my clinical practice and they really work."
"Volumetrics makes a lot of sense," agrees Rachel Brandeis, MS, RD, a former Academy spokesperson. "It's based on healthy eating and Rolls has done a lot of good studies to back up her book."
But Lona Sandon, MS, RD, also a spokeswoman for the Academy, worries that the fullness you get with a Volumetrics-approved meal might be fleeting.
"I think it's true that foods with a lot of water in them can make you feel full just after you've eaten," Sandon tells WebMD. "But the feeling might not last long. Water can empty out of your stomach quickly. I know that I might feel full right after a broth-based soup for dinner, but I feel pretty hungry a few hours later."
Brandeis points out that Volumetrics might not be the right diet for everyone. "I'm not sure if people who have trouble overeating will be able to use this plan on their own," she tells WebMD. "The whole concept of satiety can be subjective, and some people learn how to keep eating after they already feel full."
Anding points out that hunger isn't the only reason people eat. Many eat for comfort or simply out of habit even when they're not hungry -- like when they're watching TV or working at their desks. Relying on a full stomach to stop you from eating might not be enough. You'll need to change some of your behaviors, too.