Good news if you are nuts about almonds.
According to the findings of a new study by the United States Department of Agriculture (USDA), they may have fewer calories than thought.
And they are not the only food type that could be less fattening than assumed. In fact, there is a growing belief among nutritionists and healthy-eating experts that when it comes to counting calories, we may have to redo our sums – and rethink our food choices.
The latest thinking suggests that the texture of the food, its fibre content, and how it is cooked can all affect the amount of energy the body is able to get from it. Even the process of chewing food uses up energy and, therefore, burns calories.
This was clearly shown in the research on almonds. Rather than using the standard way of measuring calories, the study, published in the American Journal of Clinical Nutrition, used an advanced method to determine how many calories were absorbed during digestion of the nuts. And the difference was a substantial 20 per cent less than listed on nutritional labels.
What's more, by eating almonds in place of certain other foods, they could contribute to weight loss. "When an 84g serving of almonds was incorporated into the diet daily, the energy digestibility of the diet as a whole decreased by five per cent," says research physiologist David Baer, who headed the study.
"Therefore, for individuals with energy intakes of between 2,000 and 3,000 calories a day, incorporation of 84g of almonds into the diet daily in exchange for highly digestible foods would result in more than a pound of weight loss per month."
The same research team has also looked at pistachios and has already discovered that their calorie count is five per cent lower than previously estimated.
Respected nutritional biochemist Dr Geoff Livesey, an expert in the way our bodies use calories, is particularly excited by the findings.
"The Baer calorie study is an example of how a healthy, nutrient-dense food like almonds has 20 per cent fewer calories than previously thought," he says. "I hope we see further research in the coming years to investigate more foods, in the context of a mixed diet, and their genuine caloric values."
In the meantime the simple rule for anyone keen to follow a healthier diet is opt for fibre-rich whole foods that not only take longer to digest, keeping you fuller for longer, but might also contain fewer calories than you thought.