Most adults who want to lose weight overestimate the healthiness of their diet

Most adults who want to lose weight overestimate the healthiness of their diet

In a small study, most adults who wanted to lose weight overestimated the healthfulness of their diet, according to a preliminary study to be presented at the American Heart Association's 2022 Scientific Sessions. The meeting, held in person and virtually in Chicago November 5-7, 2022, is a premier global exchange on the latest scientific advances, research and evidence-based clinical practice updates in cardiovascular science.

"We found that while people generally know that fruits and vegetables are healthy, there may be a disconnect between what researchers and health professionals consider to be a healthy and balanced diet and what the public considers to be a healthy and balanced diet," said study author Jessica Cheng, Ph.D., a postdoctoral fellow in epidemiology at the Harvard TH Chan School of Public Health and in general internal medicine at Massachusetts General Hospital, both in Boston.

This research was conducted while Dr. Cheng is a PhD/Ph.D. candidate in the Department of Epidemiology at the University of Pittsburgh School of Public Health.

According to the Centers for Disease Control and Prevention, nearly half of U.S. adults try to lose weight each year, with the majority trying to eat more fruits, vegetables and salads. Healthy eating is important for heart and overall health and longevity. 2021 American Heart Association Dietary Guidelines advise adults to eat a variety of fruits and vegetables; opt for whole grains instead of refined grains; choose healthy protein sources; replace fat-free and low-fat dairy products with full-fat versions; choose lean meat (for those who eat meat); use liquid vegetable oils instead of tropical oils and animal fats; choose minimally processed over ultra-processed foods; minimize foods and drinks with added sugar; Choose foods with little or no added salt; and limit or avoid alcohol.

Researchers evaluated the diets of 116 adults ages 35 to 58 in the Pittsburgh, Pa., metropolitan area who were trying to lose weight. Study participants met in person with a nutritionist to discuss their diet and then tracked everything they ate and drank each day in the Fitbit app for a year. They also weighed themselves daily and wore a Fitbit device to track their physical activity.

Researchers calculated a Healthy Eating Index (HEI) at the start and end of the study based on the types of foods participants reported eating. Participants were asked to complete a 24-hour food recall at each time point for two days. The HEI is a measure of how closely a dietary pattern matches the U.S. government's Dietary Guidelines for Americans. A score from 0 to 100 is possible, with a higher score indicating a healthier diet. The score is based on the frequency of consumption of various dietary components such as fruits, vegetables, whole and refined grains, meat and seafood, sodium, fats and sugars.

Participants self-rated their initial and final quality of their diet to determine their perceived scores. Your score was also on a scale of 0-100 based on the components of the college. The self-assessment of their initial diet was a “retrospective” as they rated both their initial and final diets at the end of the study. The difference in their initial and final scores was their perceived dietary change. A difference of 6 points or less between the researcher's HEI score and the participant's perceived score was considered a “good agreement.”

At the end of the study, approximately 1 in 4 participants' ratings showed good agreement between their perceived nutritional rating and the researcher-assessed rating. The scores of the remaining 3 of 4 participants showed poor agreement, and most reported a perceived score that was higher than the HEI score assigned by the researchers. The average perceived score was 67.6 and the average HEI score was 56.4.

When assessing change in nutrition score over 12 months, only 1 in 10 participants had good agreement between their self-rated change and the researchers' change in HEI score. At the end of the study, participants improved their diet quality by about one point based on the score assessed by the researcher. However, participants' self-assessment was a perceived improvement of 18 points.

"People trying to lose weight, or health professionals helping people with weight loss or nutrition-related goals, should be aware that there is probably more room for improvement in nutrition than one might expect," Cheng said. She suggests providing concrete information about what areas of their diet can be improved and how they can make healthy, sustainable dietary changes.

“Future studies should examine the effects of helping people close the gap between their perceptions and objective measures of diet quality,” she said.

"Overestimating the perceived healthiness of food intake can lead to weight gain, frustration over not meeting personal weight loss goals, or a reduced likelihood of adopting healthier eating habits," said Deepika Laddu, Ph.D., assistant professor in the College of Applied Health Sciences at the University of Illinois, Chicago, and chair of the American Heart Association's Council on Lifestyle Behavioral Change for Improving Health Factors. "While misperception of food intake is common among dieters, these findings provide additional support for behavioral counseling interventions that include more frequent contacts with health professionals such as nutritionists or health coaches to address the gaps in perception and support long-term and realistic healthy eating behaviors."

Limitations of the study include that participants were predominantly female (79%) and the majority reported white race (84%), so the results may not apply equally to other populations. Additionally, researchers did not assess perceptions of diet quality until the end of the study. Assessments throughout the study may have helped answer questions such as: For example, whether perceptions became more realistic over the course of the study, or whether a person's perceptions of their diet help or hinder them from making dietary changes.

Co-authors are Tina Costacou, Ph.D.; Susan M. Sereika, Ph.D.; Bonny Rockette-Wagner, Ph.D.; Andrea M. Kriska, Ph.D.; Mary Lou Klem, Ph.D., MLIS; Margaret B. Conroy, MD, MPH; Bambang Parmanto, Ph.D.; and Lora E. Burke, Ph.D., MPH. Authors’ disclosures are listed in the abstract.

The study was funded by the National Heart, Lung, and Blood Institute, a division of the National Institutes of Health.

Source:

American Heart Association

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