Forget what the commercials say—fast food hasn’t gotten much healthier in the past 14 years.

You know American fast food isn’t too healthy when the restaurant making the most nutritional improvement specializes in fried chicken.

A new study published in the American Journal of Preventive Medicine shows that in the past 14 years, eight major U.S. fast food restaurants have modestly increased the nutritional value of their food, but they’re still miles away from healthy dining.

Researchers rated the quality of food from the selected restaurants using the Healthy Eating Index, a quantifying metric designed by the U.S. Department of Agriculture (USDA).

While the fast food chains improved on their 1997-1998 scores, the eight major restaurant chains scored a measly average of 48 out of 100 in 2009-2010, up from 45.

“Modest improvements in average nutritional quality of menu offerings across eight fast-food restaurant chains were observed, which is consistent with both legislative efforts (e.g., banning trans fat) and the industry’s own statements about creating healthier menu options,” lead researcher Mary Hearst, an associate professor of public health at St. Catherine University in Minnesota, said in a press release. “However, considering that fast food is ubiquitous in the U.S. diet, there is much room for improvement.”

Kentucky Fried Chicken made the most improvement—a nine-point gain on the Healthy Eating Index—by increasing the numbers of vegetables and whole grains on the menu, while cutting back on saturated fats, solid fats, and added sugars. Jack in the Box was the second most improved with a gain of seven points.

The scores for the eight restaurants (out of a possible 100 points) were:

  • Taco Bell: 56
  • Kentucky Fried Chicken: 51
  • Arby’s: 51
  • Wendy’s: 49
  • Jack in the Box: 49
  • McDonald’s: 48
  • Burger King: 44
  • Dairy Queen: 38

However, the data collection stopped in 2010, and since then there has been growing pressure on the fast food industry to offer healthier menu options. Many chains are complying, albeit in small steps.

Researchers say that about a quarter of American adults consume fast food more than twice a week.

On the whole, the average American’s eating habits aren’t great. The latest scores on the Healthy Eating Index show that from 2001 to 2008, the average American’s personal diet score moved up from 52 to 53, putting them somewhere between an order of Taco Bell’s Nachos Bellgrande and KFC’s original recipe.

In that time period, Americans did manage to decrease their sodium and empty calorie intake, while increasing their whole fruit consumption, according to the USDA.

“Given the relative influence of the fast-food industry on the U.S. diet, fast-food restaurants are in a unique position to improve the diet quality of the U.S. population by improving the nutritional quality of menu offerings,” the researchers concluded.

Fast food has an enduring place in the American diet because all too often we’re so busy that when hunger strikes, we reach for something fast and chock-full of calories.

And new research says we have leftover evolutionary skills to blame.

Anyone who’s made the mistake of grocery shopping on an empty stomach knows that if you’re hungry you’ll end up with some weird things in your basket.

Researchers at Cornell University’s Food and Brand Lab found that people who grocery shop while hungry don’t actually buy more food, but they tend to buy more high-calorie products than those without rumbling stomachs.

Their research, published this week in the Journal of the American Medical Association, underscores previous findings showing that the more we’re exposed to hardship, the more we seek high-calorie foods.

Earlier this year, researchers at the University of Miami found that in times of hardship, we’re likely to consume 40 percent more food.

This calorie hoarding is believed to be a leftover trait from our hunter-gatherer days when food was hard to come by. The longer we went without food, the more calories we needed to maintain our health.

Now that there’s an overabundance of food and the majority of us aren’t getting enough exercise—only about 20 percent of Americans get the recommended 2.5 hours of aerobic exercise and strength-training per week, according to the latest report from the U.S. Centers for Disease Control and Prevention—those excess calories add to the growing obesity epidemic in the U.S.

Check out Healthline’s Healthy Eating Center to learn more about strategic grocery shopping and fast food options and to get a better idea of what you’re up against in your fight for a healthier future.