From protein bars and shakes to high-protein cereals and snacks, protein has become one of the biggest nutrition trends in recent years.

The surge in protein-rich products has coincided with the popularity of weight-loss plans and high-protein diets, but nutrition experts say more protein isn't always better.

Nutritionists say the recommended dietary allowance for protein is 0. 8 grams per kilogram of body weight for the average adult.