Most people would agree with the assessment “you are what you eat,” yet many overlook the fact that this holds true for the food you eat, too. If the chicken on your dinner plate was fed an unnatural diet of genetically engineered (GE) soy and grains (or worse) — what essentially boils down to junk food for birds — it can’t be expected to be optimally healthy, nor optimally nutritious.

Because most poultry in the U.S. comes from concentrated animal feeding operations (CAFOs), The Guardian went so far as to state, “In 50 years, poultry has gone from being a health food to a junk food,” pointing out a study from London Metropolitan University that found, compared to 1940, chicken in 2004 contained more than twice as much fat, one-third more calories and one-third less protein, the latter being the main nutritional reason most people eat chicken.¹

Levels of healthy fats in chicken, namely beneficial animal-based omega-3s including DHA, have also changed considerably. The London Metropolitan University study, written by professor Michael Crawford of London Metropolitan University, found that eating 100 grams (about one-quarter pound) of chicken in 1980 would give you 170 milligrams (mg) of DHA, but that same amount of chicken in 2004 would provide just 25 mg.

Omega-6 fats, on the other hand — the kind most Americans get way too much of, courtesy of highly processed vegetable oils — increased, rising from 2,400 mg in 1980 to 6,290 mg in 2004.

If you’re not familiar with the importance of the omega-3 to omega-6 ratio, the ideal ratio is 1-to-1, but the typical Western diet may be between 1-to-20 and 1-to-50. Even the World Health Organization (WHO) recommends a ratio of 1-to-5 for general health and 1-to-2 for optimal brain development. CAFO chicken, and for that matter CAFO anything, certainly isn’t helping anyone achieve that goal.

Nutrition Declines When Animals Are Fed Grains Instead of Grass

Crawford told The Guardian that a large part of the problem with declining nutrition in chicken and other animal foods is the fact that nearly all livestock is fed grains instead of grass and other species-appropriate foods:²

“Animal husbandry started with grass and green foods, which are rich in omega-3. That is the beauty of [some] fish and seafood because it’s still largely wild, it’s still living in an omega-3-rich environment.

The same used to be true of livestock animals — even chickens used to roam free and live off seeds and herbs — but that is no longer the case. It really is a question of redesigning our food and agriculture systems so they are more keyed in to the pivotal priority of human physiology — namely, our original genome being shaped by wild foods.”

The American Pastured Poultry Producers Association (APPPA) also published a study that compared the nutrition of chickens fed on pasture with the USDA’s National Nutrient Database for Standard Reference values for CAFO chicken. The pasture-raised chickens were higher in vitamins D3 and E and had an average omega-3-to-6 ratio of 1-to-5, compared to the USDA’s value of 1-to-15.³

Bigger Chickens Were Made Possible by Antibiotics

You might consider the plump chicken breasts at your grocery store to be the norm when it comes to chicken sizes, but as recently as the 1920s, most people did not consider raising chickens for their meat — they were far too scrawny. At that time, chickens were raised for eggs only, but that changed around 1923, when a farmer in Delaware accidentally placed an order for too many hatchling chickens (500 instead of 50), so she sold them for meat.

In her book “Big Chicken: The Incredible Story of How Antibiotics Created Modern Agriculture and Changed the Way the World Eats,” journalist Maryn McKenna explains how this one mistake led chickens to become big business. Part of the story, unfortunately, was the discovery that feeding chickens antibiotics made them grow about 2.5 times faster.

Around that same time, in 1948, a national “Chicken of Tomorrow” contest, seeking to develop a meatier chicken, was sponsored by A&P supermarket and supported by the U.S. Department of Agriculture.

The major lines of chickens sold in the U.S. today can all be traced back to the contest’s winner. Between the use of antibiotics for growth promotion and the genetic selection of chickens that grow faster and larger, the average chicken today is four times bigger than chickens in the 1950s; chicken breasts are also 80 percent larger.⁴