From the Journals

An avocado a day doesn’t shrink belly fat, but helps with cholesterol


Avocados are a rich source of fiber and healthy fat, but eating one a day for 6 months did not shrink waist size or belly fat, according to the findings of a new study.

But it did improve diet quality and led to modest lowering of total cholesterol.

More than 1,000 adults with overweight or obesity and a large waist – at least 35 inches in women and 40 inches in men – took part in this U.S. study, called the Habitual Diet and Avocado Trial (HAT).

Avocados tookapic/Pixabay

The people in the study were divided into two groups: usual diet plus one large avocado every day and usual diet with two avocados at most per month (control group).

Those in the avocado-a-day group were given a regular supply of fresh avocados along with written instructions for how to ripen and prepare them.

They had MRI scans to measure belly fat and fat around other organs at the beginning of the study and after 6 months.

After 6 months, the people who ate an avocado a day did not have less fat around their middles – the main trial outcome – compared with people in the control group.

But at 6 months, those in the avocado-a-day group had:

  • No weight gain. People’s weight remained stable in both groups.
  • Improved diet quality by 8 points on a 100-point scale
  • A 2.9-mg/dL decrease in total cholesterol
  • A 2.5-mg/dL decrease in LDL cholesterol

The study was done by researchers at Penn State University; Tufts University; Loma Linda University; and the University of California, Los Angeles, with coordinating support from Wake Forest University.

It was published in the Journal of the American Heart Association.

“While the avocados did not affect belly fat or weight gain, the study still provides evidence that avocados can be a beneficial addition to a well-balanced diet,” Penny M. Kris-Etherton, PhD, one of the researchers and a professor of nutritional sciences at Penn State University, University Park, said in a news release.

“Incorporating an avocado per day in this study did not cause weight gain and also caused a slight decrease in LDL cholesterol, which are all important findings for better health,” she said.

Similarly, study researcher Joan Sabaté, MD, a professor at Loma Linda (Calif.) University, said: “While one avocado a day did not lead to clinically significant improvements in abdominal fat and other cardiometabolic risk factors, consuming one avocado a day did not result in body weight gain.”

“This is positive,” he said, “because eating extra calories from avocados doesn’t impact body weight or abdominal fat, and it slightly decreases total and LDL cholesterol.”

Kristina S. Petersen, PhD, another of the researchers and an assistant professor of nutritional sciences at Texas Tech University, Lubbock, pointed out that people are generally poor at adhering to the Dietary Guidelines for Americans.

This study suggests that an avocado a day can improve diet quality, she noted, which “ is important because we know a higher diet quality is associated with lower risk of several diseases, including heart disease, type 2 diabetes, and some cancers.”

But the researchers also stressed that it is important to consider the diet as a whole.

“Consistent with prior observations, a change in dietary patterns rather than a single food or nutrient may be necessary to achieve clinically significant improvements” in belly fat and other risk factors for heart attack, stroke, and diabetes, they wrote.

HAT was funded by the Hass Avocado Board, which also supplied the avocados.

A version of this article first appeared on

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