A new study suggests that meals that include fresh avocado as a substitute for refined carbohydrates can significantly suppress hunger and increase meal satisfaction in overweight and obese adults.
The study is released by the Center for Nutrition Research at Illinois Institute of Technology.
As rates of obesity in the U.S. continue to rise, the findings from Illinois Tech suggest that simple dietary changes can have an important impact on managing hunger and aiding metabolic control.
The research also shows favorable effects on glucose and insulin responses and suggests that avocado would have favorable effects for people with diabetes, particularly when replacing carbohydrate in their meals, Dr. Britt Burton-Freeman, director of the Center for Nutrition Research at Illinois Tech and one of the authors of the study, tells dLife.
How was the Study Conducted?
The new research assessed the underlying physiological effects of including whole and half fresh Hass avocados on hunger, fullness, and how satisfied subjects felt over a six-hour period.
Researchers evaluated these effects in 31 overweight and obese adults in a randomized three-arm crossover clinical trial. These dietary changes were also shown to limit insulin and blood glucose excursions, further reducing the risk of diabetes and cardiovascular disease by adding healthy fats and fibers into a regular daily diet.
“For years, fats have been targeted as the main cause of obesity, and now carbohydrates have come under scrutiny for their role in appetite regulation and weight control,” says Burton-Freeman.
She says there is no “one size fits all” solution when it comes to optimal meal composition for managing appetite.
“However, understanding the relationship between food chemistry and its physiological effects in different populations can reveal opportunities for addressing appetite control and reducing rates of obesity, putting us a step closer to personalized dietary recommendations,” adds Burton-Freeman, who is also a member of Avocado Nutrition Science Advisory.
The research found that meals including avocado not only resulted in a significant reduction in hunger and an increase in how satisfied participants felt, but also found that an intestinal hormone called PYY was an important messenger of the physiological response.
As far as whether it’s possible to over-eat avocado and consume amounts that would affect caloric intake, Burton-Freeman tells dLife it’s possible to overeat anything if we are not paying attention, and therefore we should all be paying attention to our calorie intake to maintain and manage weight.
However she points out the current study focuses on two things 1) the idea is to replace other calories in the meal with avocado calories, 2) avocados are stimulating several satiety peptide hormones as noted in the paper, and PYY is surfacing as particularly involved in mediating the satiety effects of avocado.
“This could have an effect on subsequent eating where people are less likely to snack and therefore reduce total calorie intake,” she explains.
The authors acknowledge the strengths and weaknesses of the study.
While the trial size was small, Burton-Freeman says the study was sufficient to deem the effects reliable. However, she says further studies are warranted to test follow up hypothesizes, such as satiety and energy intake effects across several days/weeks of intake.
Another study limitation was the lack of a test meal to measure subsequent food/energy intake 6 hours after meals as the meal-related time course of subjective satiety (particularly later in the postprandial period) suggested an effect on subsequent meal intake may have been plausible.
The authors also note that not separating the specific fat type and fiber effect also may be a limitation.
Lastly, they note that gut hormones were not measured after meals with half avocado. They note that this information may have provided insight into the observed differences in fullness ratings between meals that contained half avocado and control meals and whole avocado meals.
The study has been published in the journal Nutrients.
The funding for the study was provided by the Hass Avocado Board, who was not involved in the study design or the interpretation of results. They did provide the avocados for the study at the authors’ request.
- Illinois Institute of Technology. (2019, May 8). Avocados, as a substitution for carbohydrates, can suppress hunger without adding calories: Meals that include fresh avocado can significantly suppress hunger and increase meal satisfaction. ScienceDaily. Retrieved May 9, 2019, from www.sciencedaily.com/releases/2019/05/190508134529.htm