More guacamole, fewer chips: evaluating avocados and hunger

Diets high in refined carbohydrates and saturated fatty acids (SFAs), such as the Western diet, have been associated with coronary heart disease and type 2 diabetes. These diets may cause problems by increasing oxidation and inflammation in the body, as well as elevating glucose and insulin levels. On the other hand, diets high in monounsaturated fatty acids (MUFAs), such as the Mediterranean and DASH diets, have been associated with cardioprotective and beneficial metabolic effects, such as reduced levels of pro-atherogenic LDL (low-density lipoprotein)-cholesterol and improved insulin sensitivity.

A number of previous studies have established a clear link between the macronutrient profile (including dietary fiber) of a given diet and its satiety effects. Although fats are generally considered less satiating than carbohydrate and protein, studies that have used energy equivalent conditions suggest there may not be a difference in satiety from either macronutrient. Reviews have reported inconclusive results regarding the impact of high-fat meals and fiber on satiety, but this may be because of differences in study design and little agreement between hormonal and subjective measures of satiety. Moreover, these studies have been conducted primarily in healthy weight adults, whereas obese or overweight adults may react differently and potentially benefit more from these kinds of dietary changes.

Fats and fibers have been shown to slow gastric emptying, modulate glucose and insulin response, and change gut hormones that influence satiety. Studies suggest that fats stimulate the release of several satiety hormones, including Peptide YY (PYY), cholecystokinin (CCK), and glucagon-like peptide-1 (GLP-1). Delayed absorption of fats from increased fiber intake could lead to greater release of these hormones and enhance satiety, but few studies have focused on the potential combined effect of fat and fiber.

Avocados are high in fat (especially MUFAs) and fiber and have previously demonstrated reductions in desire to eat and increased meal satisfaction when compared to a meal without avocado. This led the authors of the study under review to evaluate the impact of the replacement of carbohydrate with a half (about 68 grams) or a whole (about 136 grams) avocado in energy equivalent meals on glycemic response, endothelial function, satiety, and gut hormones.

Avocados are a good source of fat and fiber, both of which have been shown to slow gastric emptying, modulate glucose and insulin responses, and change gut hormones that influence satiety. The authors of the study under review aimed to evaluate the impact of the replacement of carbohydrate with varying amounts of avocado in energy equivalent meals on glycemic response, endothelial function, satiety, and gut hormones.