The Zodiac Diet

Libra (September 23-October 22)

You're so flipping wishy-washy—sorry, magnificently diplomatic—that mid-diet you're liable to change your mind (wait, wouldn't the Zone be better?).

Best bet: A partner to keep you on track, mixed with a balanced, middle-of-the-road eating plan.

Scorpio (October 23-November 21)

You're infamously all-or-nothing in your approach to exercise and dieting. The nice part is that no zodiac sign has deeper reserves of willpower.

Best bet: Any extreme regimen that involves control over your impulses, mild self-flagellation, and full-body detoxification. Bikram yoga, anyone? Weeklong juice fast?

Sagittarius (November 22-December 21)

Prone to claustrophobia, you require freedom, challenge, and open spaces filled with gaily chirping birds. You also tend to put on weight easily, particularly in the hips and thighs.

Best bet: Go hiking rather than sequestering yourself inside a gym. As for dieting, don't even think about it. Just try to eat for health and lead a vigorous, don't-fence-me-in life.

Capricorn (December 22-January 19)

You tender, quietly driven, and occasionally melancholic souls respond well to structure.

Best bet: A systematized diet and fitness plan favoring gentler exercise (yoga, Pilates, bands) to counter your tendency to stiffen under pressure. Remember, if you want to get ahead (Capricorns are nothing if not ambitious), it won't hurt to look your best.

Aquarius (January 20-February 18)

You are the "I'll do it my way" individualist of the zodiac, and by a long shot the most intellectual of the three air signs.

Best bet: Aquarius rules the ankles and circulatory system, which is why skiing, treadmilling, and dancing are excellent calorie burners for you. And diet? Follow your own regimen, the more off the beaten track, the better.

Pisces (February 19-March 20)

Kindly, dreamy, poetical, and occasionally self-delusional, you badly need structure in your life, or else you'll start drinking gin and writing god-awful song lyrics.

Best bet: Exercise that gives you the illusion of merging with the universe—yoga, rock climbing, running. To avoid going off the deep end, opt for a rational, three-meal-a-day diet—and hang on to your scales.

More Diet Insight

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• Dr. Oz reveals 5 diet myths working against you
• Quiz: What's your diet IQ?