Not only does eating one avocado a day for six months have no effect on belly fat, liver fat or waist circumference in overweight or obese people, it also provides a better quality diet and leads to a slight decrease in unhealthy cholesterol levels.
The collaborative study team said that while prior, smaller studies have found a link between eating avocados and lower body weight, BMI, and waist circumferences, this was the largest, most extensive study to date on the health effects of avocados, including the large number of participants and length of the six-month study period.
“While the avocados did not affect belly fat or weight gain, the findings are evidence that avocados can be a beneficial addition to a well-balanced diet,” said Penny Kris-Etherton, Evan Pugh University Professor of Nutritional Sciences at Penn State.
“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.”
Kristina Petersen, assistant professor of nutritional sciences at Texas Tech University, said the study also found that eating avocados daily improved the overall quality of the participants’ diets by eight points on a 100-point scale.
“Adherence to the Dietary Guidelines for Americans is generally poor in the US, and our findings suggest that eating an avocado per day can substantially increase overall diet quality,” Petersen said. “This is important because we know a higher diet quality is linked to lower risk of several diseases including heart disease, type 2 diabetes and some cancers.”
The research, published in the Journal of the American Heart Association, was conducted in conjunction with Loma Linda University, Tufts University, and UCLA, with co-ordinating support from Wake Forest University.
The researchers conducted a six-month experiment involving more than 1 000 participants experiencing overweight or obesity, half of whom were instructed to eat an avocado daily while the other half stuck to their usual diet and were told to limit their avocado consumption to less than two a month. Fat in the abdomen and around other organs was measured precisely using MRI before and at the end of the study.
“While one daily avocado did not lead to clinically significant improvements in abdominal fat and other cardiometabolic risk factors, neither did it result in body weight gain,” said Joan Sabaté, professor at Loma Linda University School of Public Health.
“This is positive because eating extra calories from avocados doesn't impact body weight or abdominal fat, and it slightly decreases total and LDL-cholesterol.”
They also found that daily avocados resulted in total cholesterol decreasing 2.9 milligrams per decilitre (mg/dL) and LDL cholesterol decreasing 2.5 mg/dL.
The researchers said that they would continue to analyse data from the study. For example, participants were not instructed on how to eat their avocados each day, and future research could investigate how participants incorporated the avocados into their diet and whether any differences in the results are observed based on how participants ate the avocado.
Study details
Effect of Incorporating 1 Avocado Per Day Versus Habitual Diet on Visceral Adiposity: A Randomised Trial.
Alice Lichtenstein, Penny Kris‐Etherton, Kristina Petersen, Nirupa Matthan, Samuel Barnes, Mara Vitolins, Zhaoping Li, Joan Sabaté, Sujatha Rajaram, Shilpy Chowdhury, Kristin Davis, Jean Galluccio, Cheryl Gilhooly, Richard Legro, Jason Li, Laura Lovato, Letitia Perdue, Gayle Petty, Anna Rasmussen, Gina Segovia‐Siapco, Rawiwan Sirirat, April Sun, David Reboussin.
Published in the Journal of the American Heart Association on 5 July 2022.
Abstract
Background
Excess visceral adiposity is associated with increased risk of cardiometabolic disorders. Short‐term well‐controlled clinical trials suggest that regular avocado consumption favourably affects body weight, visceral adiposity, and satiety.
Methods and Results
The HAT Trial (Habitual Diet and Avocado Trial) was a multicentre, randomised, controlled parallel‐arm trial designed to test whether consuming 1 large avocado per day for 6 months in a diverse group of free‐living individuals (N=1008) with an elevated waist circumference compared with a habitual diet would decrease visceral adiposity as measured by magnetic resonance imaging. Secondary and additional end points related to risk factors associated with cardiometabolic disorders were assessed. The primary outcome, change in visceral adipose tissue volume during the intervention period, was not significantly different between the Avocado Supplemented and Habitual Diet Groups (estimated mean difference (0.017 L [−0.024 L, 0.058 L], P=0.405). No significant group differences were observed for the secondary outcomes of hepatic fat fraction, hsCRP (high‐sensitivity C‐reactive protein), and components of the metabolic syndrome. Of the additional outcome measures, modest but nominally significant reductions in total and low‐density lipoprotein cholesterol were observed in the Avocado Supplemented compared with the Habitual Diet Group. Changes in the other additional and post hoc measures (body weight, body mass index, insulin, very low‐density lipoprotein concentrations, and total cholesterol:high‐density lipoprotein cholesterol ratio) were similar between the 2 groups.
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