Nighttime avocado snack may support heart health in prediabetic adults

Findings from a newly published randomized controlled trial offer surprising insights for the one in three adults at greater risk of heart disease because of prediabetes. The study explored how snacking on avocado at night affects health markers the next morning, in line with the "second-meal effect" – the idea that the composition of a previous meal can affect how the body processes the next meal.

The results suggest snacking on avocado at night may promote healthier triglyceride metabolism the next morning. Triglycerides are the most common type of fat in the body, but elevated levels can be a sign of insulin resistance, a hallmark of type 2 diabetes characterized by the body's inability to process and turn food into energy the way it should. Many people with prediabetes have high triglycerides which put them at greater risk of heart disease.

In the study, 27 adults with prediabetes ate three different calorie-matched snacks on separate evenings: 1) one whole avocado (containing fiber and unsaturated fats), 2) a low-fat, low-fiber snack, and 3) a processed snack designed to match avocado's fat and fiber content. The emerging science shows that eating a whole avocado as a nighttime snack led to slightly lower triglyceride levels before breakfast and significantly lower levels after breakfast (3 hours after the meal), compared to the other snacks.

Our findings suggest that avocado's unique nutrient package – its whole-food matrix – may further support heart health by encouraging healthier triglyceride metabolism. While the good fats and fiber in avocados already make them a satisfying snack, this research is making us think about how snacks before bed – something 84% of people consume regularly – can influence how the body handles food later. It's really intriguing to find a positive outcome when the snack is avocado given the concerns about late-night eating contributing to increased risk of obesity and cardiometabolic conditions." 

Britt Burton-Freeman, study author and professor and chair, Department of Food Science and Nutrition, Illinois Institute of Technology

Participants in the study typically ate their snacks between 8:00 and 9:00 pm, followed by a 12 hour fast overnight. The next morning, they consumed a standardized breakfast and blood samples were collected before and after breakfast to measure triglycerides, glucose, insulin, and inflammatory markers. No significant differences were observed in glucose, insulin, or inflammatory markers. The researchers surmise that testing snack behaviors over several days versus one day may be needed to better understand the impact on these health markers.

Findings from this study, supported by the Avocado Nutrition Center, might not apply to everyone but they offer intriguing insight into the potential benefits of avocado as a nighttime snack-particularly in light of recent research about fruit and vegetable intake for sleep quality, and the connection between avocado consumption and diet quality, sleep, and blood lipids. These three factors-diet, sleep, and blood lipids-are all recognized by the American Heart Association as essential components of cardiovascular well-being.