The research published in the European Journal of Clinical Nutrition and backed by the Almond Board of California found that eating 1.5 ounces of dry-roasted, lightly salted almonds reduced hunger and improved dietary vitamin E and monounsaturated ("good") fat intake without increasing body weight.
The research suggested a “very strong dietary compensation” whereby almond snacking led participants to alter their eating habits and energy intake elsewhere leader of the study, Dr Richard Mattes, told BakeryandSnacks.com.
Mattes said that the motivation behind the study was a significant shift in dietary habits in the US and more generally. “Snacking is now contributing a larger proportion of energy to diets,” he said.
Some snacks may increase energy intake, and therefore potentially lead to weight gain, but will not fill the snacker up and will offer only empty calories of little to no nutritious value.
Scientists at the Purdue University conducted the 4-week randomized trial with 137 participants split across five different snacking groups. A control group was asked to avoid all nuts and seeds during the study period, a second group consumed 43g of almonds with their breakfast each morning, a third group did the same with their lunch, a fourth consumed the same amount as a morning snack between breakfast and dinner and the final fifth group did the same for an afternoon snack between lunch and dinner.
All the participants were aged 18-60 and at increased risk for type 2 diabetes being either overweight or obese or of normal weight with a strong family history of the disease. However the mixed gender groups were not diabetic or taking any medication known to affect glycemia, metabolism or appetite. They were also regular breakfast eaters and had a stable weight which had not changed more than 5kg in the previous 3 months.
Participants were not given any other diet or lifestyle guidance beyond their assigned group particularities. At the beginning and end of the trial the participants completed an oral glucose tolerance test and acute-feeding session.
What did they find?
After 4 weeks, anthropometric measurements and fasting blood biochemistries did not differ from the control group or across intervention groups. Without specific guidance, daily energy intake was reduced to compensate for energy from the provided almonds. Dietary monounsaturated fat and a-tocopherol (a form of vitamin E) intakes were significantly increased in all almond groups, wrote the researchers.
Despite consuming approximately 250 additional calories per day from almonds, participants did not increase the total number of calories they ate and drank over the course of the day or gain weight over the course of the four-week study.
Snacking on almonds compared to having them as part of a meal was shown to be the most effective in the moderation of blood sugar levels. When asked if he felt that the results were because of some characteristic of almonds, or simply because they were replacing an unhealthier snack, Mattes said they had yet to find the answer.
He said that despite the nuts being slightly salted, the sodium levels were lower than might be expected since the salt sits on the surface of the snack increasing perceived saltiness, in contrast with foods like processed meats, diary and baked goods which we eat a lot of and contain higher sodium levels.
Moving forward with their snacking research Mattes and his team are currently writing up research which they say shows snacking on peanuts actually reduces blood sugar levels.
European Journal of Clinical Nutrition
Published online ahead of print, doi:10.1038/ejcn.2013.184
“Appetitive, dietary and health effects of almonds consumed with meals or as snacks: a randomized, controlled trial”
Authors: S.Y. Tan and R.D. Mattes