Most of us need at least 50g of protein a day, and significantly more if we're working out a lot or trying to lose weight. This graphic shows what 25g of protein looks like in a variety of foods, so you can eat a few of these portions and know you're on the right track.
Athletes need between 0.5g and 0.8g of protein per pound of body weight per day (so, 75g-120g for a 150-pound person). Eating more than this is OK, as long as you've budgeted it into your calories for the day.
You can get a 25g helping of protein from a small portion of meat, four hard-boiled eggs or a cup of lentils. Check out the graphic for more examples from the plant and animal kingdoms.
Infographic: What 25 Grams of Protein Looks Like [DailyBurn]