Study Finds Dieters May Overestimate The Healthiness Of Their Eating Habits

A new study, presented at the American Heart Association’s Scientific Sessions in November 2022 revealed that most adults seeking to lose weight overestimated their eating habits and the healthiness of their diet.

The researchers found that while people generally know that fruits and vegetables are healthy, there may be a disconnect between what researchers and health care professionals consider to be a healthy and balanced diet compared to what the public thinks is a healthy and balanced diet.

Researchers evaluated the diets of 116 adults, aged 35-58 years old in the greater Pittsburgh area who were trying to lose weight. Participants met 1 on 1 with a dietitian to discuss their nutrition and tracked everything they ate and drank every day for 1 year. They also weighed themselves and tracked activity using Fitbit devices.

Researchers calculated a “Healthy Eating Index” score at the beginning and the end of the study.  Scores were based on frequency of eating fruits and vegetables, whole grains, refined grains, meats, seafood, sodium, fats and sugars. Participants also self-scored their beginning and ending diet quality to determine their perceived scores.  The difference between their beginning and ending score was calculated as their perceived diet change. 

At the end of the study, only 1 in 10 participants had perceived scores that matched the researcher’s scores of their diets. The average perceived score was 67.6 and the average researcher score was 56.4 (out of a possible 100).

It’s important to note that there are some major limitations to this study.  The sample size was quite small, only 116 participants and the majority of participants (79%) were female. The majority (84%) were also Caucasian so the findings may not apply to other populations. The researchers only assessed perceived diet quality at the end of the study so participants were expected to score their beginning diet after a year of working towards diet changes which increases the risk of inaccuracies. 

Another limitation is that the Healthy Eating Index a measure of how closely a dietary pattern aligns with the U.S government’s dietary guidelines for Americans which are often criticized and also means that this data may not apply to Canadian populations with different government endorsed dietary guidelines.

Considering nearly half of all adults in the US (and a similar amount in Canada) try to lose weight every single year, this data presents a huge gap in public knowledge of nutrition, and a huge opportunity for graduates of ELA’s Applied Nutrition Science Diploma program.

This demonstrates the need for further nutrition education and support for the general public and the important role that educated nutrition professionals can play in improving the health and eating habits of individuals and communities.