Macronutrients Part 2: Protein


I wrote an introductory blog about macronutrients, or “macros”. I started talking about carbohydrates, the macronutrient that most people eat the most of. Today, I’m writing about protein, the macro that I tell most people to increase when they’re trying to lose fat and gain muscle.

What is protein?
Proteins are made up of amino acids. You could consider amino acids the building blocks of protein. Amino acids are broken down into two different types: essential amino acids (the eight amino acids that our bodies can’t make up — it’s essential that we get them from our diet) and non-essential amino acids. A protein source that provides all of the essential amino acids may be known as a complete protein source (for example: meat, fish, milk, eggs, and cheese). Every part of your body needs protein, so it’s important to get enough.
The most abundant sources of protein are meats (chicken, turkey, beef, pork, fish), but other foods, like eggs, dairy products, nuts and seeds, and some grains also contain protein. It is possible — but challenging — for vegetarians to get enough protein from non-meat sources. For more information on protein intake for vegetarians, check out this great link from Savvy Vegetarian.
How much protein do I need?
This is a controversial topic. Many bodybuilders eat 200+ grams of protein a day, but most people don’t consume nearly that much. The USDA recommends that adult women get 40-50 grams and men get 50-60 grams each day. I eat around 100-150 grams of protein each day and find that it helps me stay lean and strong. Many fitness enthusiasts eat 1 to 1.5 grams of protein per pound of body weight and that’s generally considered the gold standard. Fat lose, muscle gain or simply maintenance, 1.5g per pound of body weight will do the trick.
There’s some controversy over the amount of protein a person can use (or “synthesize”) in one sitting. For a long time, people took for granted the conventional wisdom that one could absorb only 30 grams of protein at a time. Dr. Layne Norton is one of the most vocal opponents of this view — here’s a paper he wrote while he was a PhD candidate.
There’s also controversy about how much protein is too much. There is some evidence that high protein intake can harm the kidneys, but there is more evidence that high (but not excessive) protein intake is not harmful, and that warnings about high protein diets are misguided. For more, check out Mark Sisson’s great summary of the literature on this topic.
One great thing about protein is that it takes a lot of energy for your body to break it down during digestion. A calorie is a unit of energy — it may take up to 30% of the energy from each calorie of protein you eat to break it down. In contrast, fat (which you’ll read about next!) is very easy for the body to break down, so only 2-3% of the calories you eat from fat are “burned” during digestion. Think about it this way: 30% of the calories you eat from protein are essentially “freebies.” If you want more information about this, look up the thermal effect of food (or “TEF”).
When you need protein
I eat protein first thing in the morning, last thing at night, and pretty often in between. Every meal must contain protein in it. No matter what your goals, the average person generally does not get enough protein in each meal. I shoot for 20 grams or more at each meal.
Eggs are a fantastic source of protein; each large whole egg has around 6 grams of protein (the white makes up around half of that). Half a cup of cottage cheese can contain 15 g of protein. If you’re on the go, a Quest bar is a great choice at around 20 grams of protein each — about as much as a cooked 3.5 oz fillet of fish (and much easier to carry in your purse). During the day, I get protein from chicken breast, fish, protein powder, and Quest bars.
I keep protein powder in my house; in the mornings, I often make whey protein shakes. Whey is digested very quickly, so it’s great after workouts, too, when you need protein to help your muscles recover (this is when you build muscle!) Many bodybuilders and fitness types drink casein protein shakes at night — casein protein (like whey) is derived from milk, but unlike whey, it’s digested very slowly. This means that protein is getting into your muscles all night long.
Have questions about protein? Post them here and I’ll answer them for you. And stay tuned for part three on what may be the most controversial macronutrient: fat.