They say you are what you eat; what they don't tell you is that the climate reflects what you eat, too. A climate-friendly diet, one emphasizing foods that have take little energy to produce and have a low carbon footprint, is not only better for the earth, it’s also better for you.

Food production is one of the major contributors to carbon emissions and climate change. A new study makes the connection between eating a climate-friendly diet — a diet low on meats, dairy and fats — and better overall health a lot clearer.

To learn more about how daily food choices contribute to greenhouse gas emissions and climate change, researchers at Tulane University and the University of Michigan looked at the diets of over 16,000 Americans. They created a database of the various greenhouse gas emissions connected to food production and linked it with a national survey that asked people what they ate in a 24-hour period.

Food production is one of the major contributors to carbon emissions and climate change.

Diets were divided into five groups based on the nutritional quality of the foods a person ate using the U.S. Healthy Eating Index. Then each diet was ranked from the lowest- to the highest-impact groups according to greenhouse gas emissions per 1,000 calories eaten.

People whose diets had the highest carbon footprint ate foods that produced five times the emission of greenhouse gases as the diets eaten by those in the lowest group. The diets of those in the high emission group included more meat — beef, veal, pork and game — and dairy products like cheese and butter. They also ate more solid fats per 1, 000 calories than those who ate low impact group diets.

People in the lowest carbon footprint group had healthier diets, but even they weren't perfectly healthy. That's because their diets contained some items like refined grains and added sugars which are low-emission but still unhealthy; they were also likely to provide lower amounts of some nutrients, like iron, calcium and vitamin D, probably because they contained less meat and dairy foods.

According to an earlier study by the same researchers, 20 percent of Americans are responsible for nearly half of U.S. diet-related greenhouse gas emissions.

Raising cows takes a much bigger toll on the environment and atmosphere than raising the same amount of food calories from plant foods, or even chickens. Cows eat more and they produce methane, a potent greenhouse gas. Simply cutting back on the amount of beef you eat can make a big difference.

It's a win-win, and the changes to your diet don’t have to be extreme to be effective. Eating more plant foods and fewer animal foods, especially beef, reduces your carbon footprint, saves you money, lowers your risk of heart problems and cancer, and improves your overall health.

The study is published in the American Journal of Clinical Nutrition.