Following this six-week, reduced-calorie plan, you should see a healthy 1-2 pound weight loss per week. The plan is designed to help you eat a lower-calorie, nutritious diet, incorporate healthy new habits, dress more fashionably, and work positive new ways of thinking into your life. At-home exercises are mapped out each day over the 42-day period, with the intensity level increasing over time.

Phase 1 of The Park Avenue Diet is a two-week self-discovery stage that teaches the dieter how to apply each of the seven principles discussed in the book. Phase 2 is a week of "preparing for greatness" by practicing your new skills. And finally Phase 3, "making the A-list," unveils the new you.

Defying conventional wisdom, The Park Avenue Diet does not recommend regular weigh-ins.

"You don’t need a scale to tell you how you are doing, how your clothes fit, or how you feel," Fischer says.
"All the compliments you will get are better reinforcements than a number on the scale."

The book briefly addresses maintenance, suggesting a continuation of what has been practiced over the six-week period, yet it defines no particular maintenance plan. Sustain the fundamentals you learned throughout the program and it will last a lifetime, Fischer says.

However, the diet's 1,250-1,350 daily calorie level is inadequate for weight maintenance There is no guidance on increasing exercise, calories, alcohol, or adding foods, such as more dairy and whole grains.

Park Avenue Diet: What the Experts Say

Studies show that any reduced-calorie diet plan that includes exercise, like The Park Avenue Diet, is a good bet for weight loss success.

"The Park Avenue Diet is a good overall lifestyle plan, but the calorie level may not be adequate to satisfy hunger," says Elisa Zied, MS, RD, a spokeswoman for the American Dietetic Association. (Fischer suggests a snack of a slice of turkey wrapped around a carrot or celery stick if you get hungry.)

Zied likes the lifestyle approach to losing weight but says the plan is so restrictive that it may be hard to sustain. She also says the menus are generally good, with a few exceptions.

"The suggested menus are nutritionally inadequate in calcium, vitamin D, and potassium because of the limited amount of low-fat dairy and whole grains," Zied says.

Zied, author of Feed Your Family Right, suggests adding low- or non-fat dairy foods and whole grains such as popcorn to fill in the nutritional gaps and help satisfy hunger.

"You may eat a few more calories, but at least the diet will be nutritionally balanced, similar to the recommendations of the [U.S. Department of Agriculture's] Dietary Guidelines, and more satisfying so you can stick with it long-term," she says.

Zied also cautions that rigorous exercise may be challenging without adequate calories to provide necessary fuel.

The Food and Drug Administration and American Dietetic Association recommend consuming at least 1,600 calories daily to meet all of your nutritional needs.