Ask the Diet Doctor: What's the Best Protein Source?

Find out when seeking out specific foods is more work than it's worth



Does where I get my protein really matter as long as I'm eating protein?

A: As long as you're eating a well-rounded diet, the source of protein isn't as important as the fact that you're eating protein. But before people start tweeting that I condone SPAM as a quality protein source, allow me to elaborate and clarify a few things.

Much of the confusion surrounding protein centers on the plant vs. animal protein debate. Is one truly better than the other? Thanks to nasty processed animal products like SPAM and other processed meats that are pumped full of nitrates and sodium, plant protein certainly paints a prettier picture in your head. But if we remove those types of foods from the discussion, the short list of plant vs. animal proteins looks something like this:

Plant Protein

  • Soy
  • Nuts and Seeds
  • Pea or Hemp Protein
  • Whole Grains (minimal protein)
  • Beans and Legumes

Animal Protein

  • Lean Beef
  • Poultry
  • Eggs
  • Dairy (milk, cheese, etc.)
  • Fish

If you are choosing your protein sources from these lists, one is not going to give you an advantage over the other in the context of your whole diet.

Incomplete Proteins: Do They Matter?

Whether a protein is complete or incomplete has to do with its level of essential amino acids (the protein building blocks that your body cannot make on its own). Unlike complete proteins, an incomplete protein does not contain all nine essential amino acids. Animal proteins are always complete proteins, but plant proteins like those found in beans and in many grains are not.

This is important information for people working to improve the nutritional status of a rural community where meat is a rare luxury; but not so much for the Manhattan ad executive who decides to have the lentil salad for lunch instead of the salmon. The fact that lentils are an incomplete protein doesn't matter to the ad executive because she may have had a complete protein for breakfast, or she'll have complete proteins when she eats Greek yogurt as an afternoon snack or when she has a tofu stir-fry for dinner. The point is that you're better off putting your energy toward eating an overall well-rounded diet than getting caught up in the micronutrients of every single meal and snack.

Plant Protein and Blood Pressure

A number of large, population-based studies have linked high intake of plant, but not animal, protein with lower blood pressure and better heart health. While this is a very positive step, the actual cause and effect nature of this relationship has not been determined, so don't toss out your rosemary shrimp skewers for a chickpea burger just yet. Additionally, low-fat diary, a complete animal protein, has been key to the blood pressure lowering effects of the DASH diet for almost two decades.

The Bottom Line

Both plant and animal proteins have their advantages. Eat them both (at least one at every meal) to optimize your protein intake and reap protein's lean-body benefits.

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