Avoid Unhealthy Habits

1. 
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   Avoid yo-yo dieting. Once you've lost weight thanks to your improved lifestyle, then work hard to maintain your weight instead of cycling up and down the scale.
    
2. 
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   Stay away from fad diets. Avoid liquid diets, diet pills and other diet supplements unless you are under the supervision of a physician.
    
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   Exercise in moderation. Working out too long, too often or with too much intensity can increase your risk for injury. Make sure to build in some rest periods between your workouts.
    
4. 
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   Know what you weigh. Being overweight and being underweight are not healthy states of being. Consult your doctor or a reputable weight chart that shows ideal weights for your age and body type.
    
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   Avoid excessive smoking and alcohol intake.
    
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   Get plenty of sleep. Studies have shows that those who sleep less tend to weigh more.

http://www.wikihow.com/Live-a-Healthy-Lifestyle