Nuts are a fantastic snack; filling, satisfying and high in protein.
The general consensus was that we still had to keep our intake in check, because they were also high in fat and calories.
But it turns out that we’ve been overestimating the calorie content of everyone’s go-to snack.
You see, research reveals that almonds have 32% fewer calories than we previously thought. Walnuts have the next biggest drop, with 21% fewer calories and the calorie-content of cashews are also down 16%.
So how did we get it wrong?
The problem was that nobody has closely studied the calorie content of whole nuts until recently.
A calorie is simply a way to measure the fuel in food.
Think back to high school science lessons. If you burnt a food, then measured the temperature of a beaker of water above the fire, you could determine how much fuel that food contained.
That’s how we know that the body can extract approximately nine calories from every gram of fat and about four calories per gram of protein, because each food group is digested differently.
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The reason it’s hard to stop chomping on nuts is that they are addictively crunchy. This is thanks to their tough cell walls. But because they’re so tough, it means that sometimes the nutrients in nuts, such as the fats, can’t escape so our bodies don’t completely digest them.
So chopped nuts or nut butters make it easy for your body to absorb all their fat and protein, whereas whole nuts can be eliminated by the body with nutrient-containing cells intact.
The science-y bit
This may be a bit too TMI, but here it is anyway.
Researchers from the United States Department of Agriculture followed the diets of people that ate food with and without nuts.
To determine the calorie content of their diets before eating and after elimination, they dried and burned the food they ate. They repeated this process with their poo, to determine how many calories were left over after their bodies had digested the food.
Once you get over the poop-factor, another interesting detail emerges.
While the official serving of cashews contains 137 calories, it’s just an average. Everyone extracted a different amount of calories, one person’s was as low as 105 and another got 151.
Which is an important reminder that calorie counting is a more a guide than a strict mandate.
So the good news for nut lovers is that eating the whole version isn’t that bad for you. But that doesn’t mean you have permission to go buck-wild and eat the whole packet.