The Fit Girl's Guide to Protein

Your all-in-one handbook to the star muscle builder in your kitchen.

Steak Cobb Salad

How much protein do I really need?
The RDA suggests 0.83 grams of protein per kilogram of body weight for the average woman (about 53g for a 140-pound woman). But a bodybuilder or active recreational athlete needs a bit more—between 1 and 2 grams per kilogram of body weight, according to the National Academy of Sports Medicine (NASM). For an active woman who weighs 140 pounds, that’s about 64–127 grams daily.

Does it matter when I eat it?
Since your body is always repairing and building tissue, you need to constantly replace your protein stores. Otherwise, you’ll start to break down protein from muscle to make glucose for fuel. Aim to consume 4 to 5 ounces (or 25–30 grams) of protein every 2.5–3.5 hours (about five to six times a day). Great sources include eggs, milk, meat, fish, poultry, cottage cheese, Greek yogurt, quinoa, amaranth, bulgur, tofu, and combinations like beans or lentils and rice (which together make complete proteins). A balanced lunch might be 4 ounces of grilled chicken over salad with a rainbow of fresh vegetables; an energizing afternoon snack might include 6 ounces of Greek yogurt or ¾ cup of low-fat cottage cheese with some nuts and fresh berries.

Is it possible to get too much protein?
Yes. Your body can absorb only about 30 grams of protein (4–5 ounces) at a time, so if you take in more than that, you’ll store the excess as fat.

Following a high-protein diet (one where protein makes up more than 40% of your daily total caloric intake) can also put a strain on the kidneys, which have to work harder to remove the by-products of protein digestion. For every gram of protein consumed above 2 grams per day, about 1–1.5 milligrams of calcium is also excreted, which leads to loss of bone density. Aim for macronutrient ratios of no more than 40% protein, 30–35% carbs, and 25–30% fats.

Can protein help me lose weight?
Yes. Higher-protein foods require more work as your body breaks them down to use for fuel, so you’ll naturally burn more calories to digest them. Plus, high-protein foods help you feel fuller longer, so you’re less likely to snack or overeat. Research published in the American Journal of Clinical Nutrition also shows that higher protein intake (about 30–40% of the diet) helps to boost levels of the hormone leptin (the so-called satiety hormone), while reducing levels of the hunger hormone ghrelin, helping you stay satisfied after meals or snacks.

What if I don’t get enough protein?
Your body uses its own muscle stores for fuel when there’s a lack of protein. That’s especially bad when trying to build lean muscle. To get the gains you want at the gym (and recovering post-workout), consume either complete amino acids (like dairy or meat) or a combination of incomplete (such as rice and beans) at every meal and snack.

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