Category Archives: Nuts

We Absorb Fewer Calories When We Eat Whole Foods (The Case Of Almonds)

AlmondServing3

This is what a 1-ounce serving of almonds looks like (about 22 nuts).

For a while now I’ve been saying that the calories listed in food tables and data bases are really just rough guides, e.g  you’ll never be able to pack a measuring cup the same way twice, especially with a whole food.  Two peaches (or apples or carrots, etc.) have different sugar contents, and so, different calorie counts. (Which is why listing a food’s calories to two decimal places, as USDA’s Nutrient Database does, is pure fantasy. Although you do need benchmarks.)

That is all beside the issue of how many calories we actually absorb. Remember my write-ups about resistant starch? Some of the starch we eat (in pasta, potatoes, bananas) never gets digested and ends up feeding the bacteria in our colons instead of feeding us.  So, 200 calories of pasta does not deliver 200 calories.

Here’s a little study that found quite a discrepancy between the calories listed for almonds, and the calories participants absorbed from those almonds:

Discrepancy Between The Atwater Factor Predicted And Empirically Measured Energy Values Of Almonds In Human Diets, American Journal of Clinical Nutrition, August 2012

The Atwater general factors (you may know them as 4 kcal/g for protein, 9 kcal/g for fat, and 4 kcal/g for carbohydrate) predicted that a 28-gram serving (about 23 almonds) would contain 170 calories. Participants in this study only absorbed 129 calories. The listed calories were overestimated by 32%.

And get this … It wasn’t just calories from almonds that were poorly predicted. Eating almonds caused an across-the-board reduction in total calories for the day. The calories, mostly fat calories, were excreted in feces:

The digestibility of macronutrients and energy from the diet as a whole was significantly affected by the addition of almonds to the diet (Table 3). The fat digestibility of the total diet decreased by nearly 5% when 42 g almonds were incorporated into the daily diet and by nearly 10% when 84 g almonds were incorporated into the diet daily (P < 0.0001).

When an 84-g serving of almonds was incorporated into the diet daily, the energy digestibility of the diet as a whole decreased by ∼5%. Therefore, for individuals with energy intakes between 2000 and 3000 kcal/d, incorporation of 84 g almonds into the diet daily in exchange for highly digestible foods would result in a reduction of available energy of 100–150 kcal/d. With a weight-reduction diet, this deficit could result in more than a pound of weight loss per month. Nuts and peanuts, being relatively energy dense and high-fat foods, may be expected to contribute to weight gain. However, both epidemiologic studies and intervention studies have suggested otherwise (17–24). These studies show that despite incorporation of nuts into the diet, there were no increases in body weight or fatness.

There are also studies showing this effect with peanuts. Participants absorbed fewer calories (primarily from fat) when the peanuts were whole, more calories when the peanuts were ground into peanut butter, and still more when they ate “isocaloric” peanut oil.

Can you imagine what a mess this makes of studies that try to provide isocaloric diets? Depending on the food, you could be off by 5% to 10%.

This is why it’s better to eat foods as minimally processed as possible. This is also why, probably, the men in that pistachio study could add – a pure add, not a substitution – 120 pistachios a day to their diet and not gain weight or increase their BMI or waist circumference.

Nuts

Shaun, since you were asking about nuts, here’s Dr. Greger’s video today. He must have heard you!

Here’s that first study: Association of Nut Consumption with Total and Cause-Specific Mortality, New England Journal of Medicine, November 2013

“Conclusions: In two large, independent cohorts of nurses and other health professionals, the frequency of nut consumption was inversely associated with total and cause-specific mortality, independently of other predictors of death.”

It was dose dependent too, the more often one ate nuts, the lower their risk for early death. Hazard ratios:

0.93 for the consumption of nuts less than once per week
0.89 for once per week
0.87 for two to four times per week
0.85 for five or six times per week
0.80 for seven or more times per week

The lower that number, the lower the risk for death. So, 0.80, or daily nut consumption, is better than 0.93, less than once a week.

That study was funded in part by the nut industry. He noted later that this study had no ties to the nut industry:

Health Benefits Of Nut Consumption With Special Reference To Body Weight Control, Nutrition, January 2012

“Nut consumption has been associated with several health benefits, such as antioxidant, hypocholesterolemic, cardioprotective, anticancer, anti-inflammatory, and antidiabetic benefits, among other functional properties.

Because nuts are energy-dense foods with high-fat content, there is a misconception among consumers that increased consumption may lead to unwanted gain in body weight with the risk of developing overweight/obesity. Nonetheless, available epidemiologic studies and short-term controlled feeding trials have supported the theory that the inclusion of nuts in the typical diet does not induce weight gain, despite an expected increase in total caloric intake.”

And that pistachio study!

Effects Of Pistachios On Body Weight In Chinese Subjects With Metabolic Syndrome, Nutrition Journal, April 2012

Participants added either no pistachios, 42 g pistachios (70 nuts), or 70 g pistachio (120 nuts) a day to their diets for 12 weeks. Look at this…

PistachioStudy
Body weight (A) and BMI (B) in 12 weeks. – ◆- dietary control group (DCG), -■-recommended serving of pistachio (RSG), -▲-high serving of pistachio (HSG).

Completely level lines … There were no significant changes in body weight, BMI, or waist-to-hip ratio, in any groups during the study. Also, 2-hour postprandial glucose was lower in the pistachio-eating groups after 12 weeks.

Add 120 pistachios a day to your diet and not gain weight? How is that possible? Who knows, but…

“Studies have suggested that the lipid in nuts is more poorly absorbed than from other food sources.”

Boy, a calorie sure is not a calorie.