ReZoom

This is the third in ReZoom's series about diets, some currently popular and others long-standing. We will look at what works, what doesn't work and at the end, wrap it up with a fun look at some really wrongheaded fad diets.

How Wrong Can Jennifer Aniston Be?

OK, maybe an unfair dig, but the Zone Diet was once referrred to as the "The Jennifer Aniston Diet" because she was such a proponent of the plan. It's less popular these days than, say, the South Beach Diet — but it was more groundbreaking.

Big in the mid '90s, the Zone Diet was also the rage with many other celebs, including Cindy Crawford and Aniston's former hubby Brad Pitt. Like other low-carb diets, it's based on the idea that a diet high in refined carbohydrates stimulates too much insulin production and, consequently, fat.

According to the diet's creator, Dr. Barry Sears, when fat "goes bad," inflammatory hormones called eicosanoids trigger inflammation and cause a variety of systemic problems like diabetes, heart problems and premature aging. For those reasons and a few others, the diet's health benefits get a pretty big thumbs-up from nationally recognized health and fitness expert Jonny Bowden.

"The Zone Diet is one of the best thought out plans in dieting history, and is probably responsible for having generated the most research, even though its creator — Dr. Barry Sears — is not credited as often as he should be," Bowden says. "Because the Zone was a more 'reasonable' and less extreme program than some of the other 'anti-establishment' programs, it was harder to dismiss as a 'fad' diet."

A Balancing Act

The plan requires that every meal and snack incorporate 40 percent of its calories from carbohydrates, 30 percent from protein and 30 percent from fat: hence, the now well-known 40:30:30 ratio. By eating a combination of foods that reduce insulin, the diet can control insulin levels. It also calls for the addition of fish oils, which are widely known for reducing inflammation in the body, as well as other health benefits such as for heart and brain function.

The Hard Part — Isn't There Always One?

Understanding the ratio is not difficult. The diet has developed "zone food blocks." Each block contains a certain about of carbs, protein and fat, and a certain number are allotted for each meal. Zone blocks are calculated according to a person's weight and height. In general, the bigger you are, the more blocks allowed. With help from the Zone's website (and other diet websites, too) calculating the daily number of blocks you should have and how they should be divided throughout the day is the easy bit. Creating meals that have the perfect ratio proves a little difficult and time-consuming for some. The diet provides packaged meals and snacks, but a steady staple of prepackaged foods is likely not what Dr. Sears had in mind.

However, Bowden says, the planning is worth the health benefits.

"Well-balanced, and grounded in excellent science, it is a terrific place to start for most people," Bowden says. "Some may need more carbs, some may need less, and the calories and amounts may need adjustment. But as a basic starting template, the 40/30/30 plan is very hard to beat. And research has shown that even in those cases when it doesn't produce greater weight loss than a competing plan of equal calories, it almost always produces improvements in blood lipids and insulin. Bottom line: It's a very healthy way to eat."

If you have the time and the inclination, the Zone Diet uses sound health principles to promote a lifetime of healthy eating habits.

Previously: Already featured in ReZoom's diet series:

• The Mediterranean Diet

• The Atkins Diet

Coming up next: The South Beach Diet and Weight Watchers.

Look for more from Jonny Bowden when he becomes a regular contributor for ReZoom next month. Bowden is the author of "The 150 Healthiest Foods on Earth," "Jonnny Bowden's Shape Up!" and "Jonny Bowden's Shape Up Workbook."