A study comprising adults with overweight and obesity showed almond consumption helped improve crucial appetite-regulating hormones.

Appetite regulation and weight management are complex. People eat not only for hunger, but for a variety of other reasons, such as stress, boredom, excitement, and so much more, which can lead to overweight/obesity. Addressing the challenge of overweight/obesity requires a multifaceted approach with innovative thinking, and new research about almonds is doing just that. 

The rates of overweight and obesity are a growing public health concern. Modulating appetite through better hormonal responses is a promising approach for assisting weight management. Research continues to explore how almonds can be a simple, effective addition to weight loss plans. A paradox of this is that almonds' caloric density does not increase body weight, body mass index (BMI), or body fat, and may decrease waist circumference.

This new research from nutrition scientists in Australia set out to better understand why consuming almonds may lead to more effective weight management. Dr. Alison Coates and her collaborators studied how almonds affected appetite, including the hormones that help regulate appetite. The study was funded by the Almond Board of California.

"Different foods impact people differently," said Dr. Coates, professor of human nutrition and director of the Alliance for Research in Exercise, Nutrition, and Activity at the University of South Australia. "Calories are important, but we think there's more to the story than that. Our understanding of almonds is evolving as nutrition researchers apply the scientific method to explore these important topics. For one, consumers who eat tree nuts, like almonds, have a lower risk for obesity. But what's so special about almonds? We wanted to dig into that. We thought something beneficial must happen on a hormonal level when almonds are added to the diet."

In her research, Dr. Coates hypothesized that almonds would have a favorable effect on the hormones that regulate appetite, as well as impact the study participants' perception of their appetites. Furthermore, the researchers wanted to know if an almond snack would help reduce subsequent consumption of calories compared to a standard carbohydrate-based snack.

The study involved 140 individuals with overweight or obesity (42 males, 98 females), aged 47.5 years (+ 10.8 years). Participants consumed unsalted, whole, natural almonds with skins (intervention) or an oven-baked fruit cereal bar (control) and had measured their levels of appetite-regulating hormones and self-reported appetite ratings over a subsequent 2-hour period. The almond portion provided was approximately 30 to 50 grams almonds (depending upon which calorie level the participant followed). A subset of participants was then invited individually to dine freely at a buffet over a 30-minute period. Appetite ratings were measured at the conclusion of the buffet experience. Researchers explored if almond consumption, when compared to the carbohydrate snack, influenced how much people would consume from the buffet.

Researchers measured appetite-regulating hormones: ghrelin, glucose-dependent insulinotropic polypeptide, glucagon-like peptide-1, leptin, pancreatic polypeptide, peptide YY, C-peptide, glucagon, and cholecystokinin. 

C-peptide response was 47% smaller with almonds compared to the carbohydrate snack (p < 0.001). Decreased C-peptide activity indicates lower insulin response, which may have implications for the development of diabetes and cardiovascular disease. Almonds may reduce the glucose response and over time may help reduce insulin resistance when consumed with a high carbohydrate food or meal. Additionally, glucose-dependent insulinotropic polypeptide, glucagon, and pancreatic polypeptide responses were larger with almonds versus the carbohydrate snack (17.8%, p = 0.005; 38.74%, p < 0.001; 44.5%, p < 0.001, respectively). Glucagon promotes satiety and may encourage weight loss, while pancreatic polypeptide lowers appetite, reduces food intake, and helps food remain in the stomach longer.

Cholecystokinin, ghrelin, glucagon-like peptide-1, leptin, and peptide YY responses were not different between the almond or the snack bar groups. Neither did self-reported appetite ratings differ significantly between the groups. However, the group treated with almonds consumed about 100 fewer calories at the buffet, although the finding was not statistically significant (exact calorie reduction was 72 calories).

Appetite regulation is complex, and consuming fewer calories may be important clinically and for public health when viewed over extended time across populations. "Think about what the calorie reduction each day over the course of a year would mean for weight management," said Dr. Coates. "That would contribute to a positive reversal in the gradual, nearly imperceptible weight gain many people experience yearly, compounded over a lifetime. I'm excited about the promise of almonds, how they can help us reshape public health."

While several of the main appetite-regulating hormones for the almond group responded favorably, that did not translate to a decrease in self-reported appetite or to statistically significant reduced short-term energy consumption. But this is not surprising. "Published research tells us there's often no direct correlation between appetite hormones, appetite ratings, and subsequent energy intake," Dr. Coates explained.

Moreover, since obesity is characterized by a resistance to appetite-regulating hormones, there could be a misalignment between the body's hormonal signals and perceptions of fullness in individuals with overweight and obesity. Regardless, almonds' nutritional profile may contribute to the satiating properties that explain why the buffet eaters consumed fewer calories. One ounce (28 g) of almonds includes 6 g protein and almonds are a good source of fiber. Scientific evidence suggests but does not prove that eating 1.5 ounces per day of most nuts such as almonds may reduce the risk of heart disease. One serving of almonds (28 g) has 13 g of unsaturated fat and only 1 g of saturated fat.

While the findings from this research are encouraging, there are some limitations to consider. A COVID-19 overlay resulted in restrictions on the number of participants who could complete the buffet challenge. In addition, as noted before, all participants had elevated body weight. Future research could examine how healthy-weight individuals respond to almond snacks and provide insight into the possible prevention of overweight and obesity. Lastly, the research team recommends that future studies investigate implications for longer-term appetite regulation.

In conclusion, the study indicates almond consumption resulted in improved hormonal responses, which reflects better control of insulin release and better blood glucose regulation. Regular almond consumers may also be more likely to consume fewer calories and manage weight better.

One ounce (28 g) of almonds provides 4 g fiber and 15 essential nutrients, including 77 mg magnesium (18.3% DV), 210 mg potassium (4% DV), and 7.27 mg vitamin E (50% DV).