1. the act of attenuating or the state of being attenuated. 2. (General Physics) the loss of energy suffered by radiation as it passes through matter, esp as a result of absorption or scattering.
A healthy teenage boy may have a higher calorie intake of about 2,200 calories per day; about 61 to 86 g of fat should be consumed. Read more: http://www.livestrong.com/article/399246-a-teen-needs-how-many-grams-of-fat-per-day/#ixzz2QFhZ92Aj. For both teenage boys and girls, 5 to 6 tsp. of fat are recommended daily. Fat can't always be measured by the teaspoon, however, so it is easier to think of fat in actual percentages.
Regardless, the teen runner will need 0.5 to 1 grams of protein per pound of body weight per day. So if your child weighs 120 pounds, he should have a daily protein intake of 60 to 120 grams of protein. Examples of proteins are fish, meat, and tofu. To reach this protein requirement, a teen runner should eat between 200 to 400 grams of meat and fish.