The National Institute of Diabetes, Digestive and Kidney Diseases (NIDDK) states that:

Women with waist-to-hip ratios of more than 0.8 are at increased health risk because of their fat distribution.

Men with waist-to-hip ratios of more than 1.0 are at increased health risk because of their fat distribution .

Excess fat in the abdominal region poses a greater health risk than excess fat in the hips and thighs and is associated with a higher risk of high blood pressure, diabetes, early onset of heart disease, and certain types of cancers. (American Dietetic Association)

Apples and Pears

The apple or pear shape is an anecdotal way of classifying women's body shapes. the general rule is: WHR (Waist-to-Hip Ratio) on or above 0.8 - you are an apple shape. WHR under 0.8 - you are a pear shape. Read more about Apples and Pears.

Ideal Waist Hip Ratio and Attractiveness

There is plenty of talk on what constitutes an ideal waist to hip ratio. Ideal to whom? Yourself or someone that looks at you? The "supposed ideal" is just under 0.7 (source)