Next time you're feeling bad about not having all your sh*t together, consider this: new research has found that only 2.7 percent of the US adult population meets all four basic criteria that scientists agree constitutes a 'healthy lifestyle'.

While that might be great news for your self esteem if you're one of the select few, it's pretty terrible in terms of public health. "The behaviour standards we were measuring for were pretty reasonable, not super high," said lead researcher Ellen Smit from Oregon State University. "We weren't looking for marathon runners."

The four criteria the researchers were looking for were: being a non-smoker, having a recommended body fat percentage, having a good diet, and doing moderate exercise - which the researchers classified as getting at least 150 minutes of moderate to vigorous physical activity each week.

In other words, the type of advice that doctors all over the world have been giving their patients for years.

The researchers were looking into how these criteria were linked to biomarkers that signal the risk of someone developing cardiovascular disease. But the biggest shock for them was just how few people actually met all four.

"To have so few people maintaining what we would consider a healthy lifestyle … is sort of mind-boggling. There's clearly a lot of room for improvement," said Smit.

To figure out the health of the nation, the team looked at a group of 4,745 people that had been randomly selected from across the country by the US National Health and Nutrition Examination Survey. (Granted that's not the same as studying the entire country, but it's a large dataset, and scientists regularly use groups such as these to gain insight into the rest of the population.)

To assess who met the criteria, they used the most reliable techniques they could find, including blood samples to figure out if someone was a smoker or not, x-ray absorptiometry to identify body fat percentage, and an accelerometer to specify whether someone was active enough.

The only criterion in the study based on self-reported data was the healthy diet, and was defined as being in the top 40 percent of people who ate foods recommended by the US Department of Agriculture (USDA).

The researchers found that:

  • Only 2.7 percent of all adults had all four healthy lifestyle characteristics
  • 16 percent met three of them
  • 37 percent ticked off two
  • 34 percent had only one of the characteristics

The easiest criterion to tick off was not smoking - 71 percent of adults had achieved that (high fives). But only 10 percent had a healthy level of body fat, just under half (46 percent) were sufficiently active, and only 38 percent ate a healthy diet.

The study covered all genders, ages, and backgrounds, and while a few trends emerged, overall, it painted a pretty bleak picture for everyone.

The (slightly) good news is that, while meeting all four criteria was generally associated with having better cardiovascular risk biomarkers than meeting none of them, there were some behaviours on their own that made a bigger difference than others.

The researchers were looking at things such as blood pressure, cholesterol, glucose levels, and fasting triglycerides, and found that even achieving just one or two healthy lifestyle characteristics improved those markers - for example, having a healthy body fat percentage was particularly important when it came to cholesterol levels.

The research has been published in Mayo Clinic Proceedings.