Almonds have fewer calories than previously thought
By Bakers Journal
By Bakers Journal
July 13, 2012, Modesto, Calif. – A study conducted by scientists from
the United States Department of Agriculture (USDA) shows that
whole almonds provide about 20 per cent fewer calories than originally
July 13, 2012, Modesto, Calif. – A study conducted by scientists from the United States Department of Agriculture (USDA) and released in the August issue of the American Journal of Clinical Nutrition (AJCN) provides a new understanding of almonds’ calorie count, showing that whole almonds provide about 20 per cent fewer calories than originally thought.
At first glance, the study results beg the question, how can a food's calorie count suddenly change when the composition of the food itself hasn’t?
David Baer, PhD, and his team from the USDA's Agricultural Research Service (ARS) used a new method of measuring the calories in almonds, which built on traditional methods and allowed the researchers to determine the number of calories from almonds that are actually absorbed during digestion. Resulting data showed a 28-gram serving of almonds (about 23 almonds) has 129 calories versus the 160 calories currently listed on food package labels. These results not only may lead people to choose almonds more often as a smart snack, but they also may have implications for certain other foods as well. The same research team also recently conducted a similar study using pistachios, finding a five per cent decrease in pistachios' calorie count compared to the 20 per cent decrease in almonds.
In the study’s discussion section, the authors considered the potential implications of substituting other foods with almonds in a calorie-controlled study. Based on the data, "When an 84-gram serving of almonds was incorporated into the diet daily, the energy digestibility of the diet as a whole decreased by five per cent. Therefore, for individuals with energy intakes between 2,000 and 3,000 kilocalories per day, incorporation of 84 grams almonds into the diet daily in exchange for [the same number of calories from] highly digestible foods would result in a reduction of available energy of 100 to 150 kilocalories per day. With a weight-reduction diet, this deficit could result in more than a pound of weight loss per month."
The new study’s results support previous research indicating that the fat in almonds is not completely absorbed during digestion, due to almonds' natural cellular structure, which encapsulates the fat, thereby impeding its absorption. This implies that traditional methods of calculating calories overstate those calories coming from almonds because they do not account for the incomplete digestibility and absorption of fat and the other macronutrients.
Traditionally, a food's calorie counts is calculated based on a system developed by Atwater et. al. more than 100 years ago. Known as the Atwater general factors, the system assigns calorie values for every gram of protein, fat and carbohydrate found in a given food (four kilocalories per gram for protein, nine kilocalories per gram for fat and four kilocalories per gram for carbohydrate). However, as the new study notes, “There have been few, if any, studies that looked at the calorie value of a whole food when consumed as part of a mixed diet that could confirm the accuracy of Atwater’s coefficients.”
So, for this study, the researchers expanded on Atwater's approach, using a specially designed diet and new method of calculation that allowed them to understand the calories provided by almonds when eaten as part of a mixed diet.
The results reported in the study are applicable only to whole almonds, and while no additional studies have been conducted yet, the discrepancy in calories may not be consistent for other forms of almonds such as almond butter or slivered or sliced almonds as the finer particles may lead to more complete digestion. Globally, however, whole almonds are consumed in far greater proportion than are other forms.
The California almond industry is now working with government agencies to determine what these study results may mean for future consumer education about almonds, such as nutrition labeling.