Randomized controlled trials are the gold standard of science.

In these studies, people are randomized into groups. For example, one group eats diet A, while the other group eats diet B.

Then the researchers follow the people and see which diet is more likely to lead to a particular outcome.

Several randomized controlled trials have examined the health effects of red meat directly.

A few studies investigated the effects of red meat on risk factors for heart disease.

One review of controlled studies concluded that eating half a serving or more of red meat daily doesn’t adversely affect heart disease risk factors such as blood lipids and blood pressure ( 20 ).

Another review showed that lean, unprocessed beef doesn’t negatively affect people’s blood lipids, compared to poultry or fish ( 21 ).

As a rich protein source, red meat can also benefit muscle growth in people doing strength exercises.

A study in older women showed that eating 160 grams of red meat six days of the week for four months enhanced muscle growth resulting from strength training, compared to pasta or rice ( 22 ).

Red meat also decreased the levels of the inflammatory marker IL-6 ( 22 ).

Keep in mind that all of these studies examined lean red meat. To date, no studies have examined the health effects of high-fat red meat.

However, there are plenty of studies that compare high-fat diets with low-fat diets.

These studies have the primary goal of reducing saturated fat, which means that the people in them have to eat less red and processed meats, which happen to be high in saturated fat.

The Women’s Health Initiative was a study in over 46,000 women. One group was instructed to eat a low-fat diet, while the other group continued eating the standard Western diet.

After a period of 7.5 years, there was almost no difference (only 1 lb/0.4 kg) in weight between groups. There was also no difference in the rate of heart disease or cancer ( 23 , 24 , 25 , 26 ).

One randomized controlled trial compared the Atkins diet (high in red meat) to the Ornish diet (a low-fat vegetarian diet with no red meat). It is called the A to Z weight loss study ( 27 ).

After one year, the Atkins group had lost more weight and had greater improvements in some of the most important risk factors for disease.

Many other studies compared low-carb (high in red meat) and low-fat (low in red meat) diets. In these studies, low-carb diets lead to much better health outcomes ( 28 , 29, 30).

Taken together, these studies suggest unprocessed red meat doesn’t adversely affect health and may even have benefits.

However, more studies need to examine whether it affects hard endpoints like heart disease and cancer. The roles of cooking methods and processing techniques also need to be studied further.