I love to eat junk food but lately I have been noticing that my junk food habits are sticking with me a little. It makes me wonder how many chocolate chip cookies I can eat before I gain a few.

There's a new study from the  Washington Post on weight gain in the "New England Journal of Medicine" that breaks down exactly how much different food and lifestyle choices affect your weight over a four-year period.

For foods, the worst thing you can eat is:

  • Potato chips. Eating chips daily or almost daily leads to a 1.69-pound gain over four years. Regularly eating other forms of potatoes, including fries, leads to a 1.28-pound gain over four years.
  • Sweets and desserts lead to weight gain but not quite as bad as potatoes. Eating dessert daily only leads to a 0.41-pound gain over four years, or about a tenth of a pound a year.
  • Drinking non-diet soda daily adds one pound every four years.
  • Red meat adds 0.93 pounds a year.
  • People who drink alcohol each day gain 0.41 pounds per drink over four years. So having four drinks a day leads to about 1.6 pounds in weight gain.

The foods that are best for you are:

  • Yogurt, which causes a loss of 0.87 pounds in four years.
    Nuts, which lead to a loss of 0.57 pounds.
  • Fruits, which lead to a loss of 0.49 pounds.
  • Vegetables lead to a 0.22-pound loss.

For behaviors, exercise is the best way to lose weight . . . no, really. People who regularly exercised lost 1.76 pounds in four years. People who smoked gained 5.17 pounds in four years. People who watch TV gained 0.31 pounds per hour of TV a day they watch in four years, so if you watch four hours of TV a day, that's about 1.2 pounds gained in four years.

Remember, these are just guidelines. If you love potatoes, you don't have to give them up, just eat them in moderation and balance them with other healthier foods.