Whole Grain Sandwich Loaf

Yes, Whole Grains Are the Real Deal for Metabolic Health

Here’s a bit of nutrition advice that holds up pretty well under close scrutiny. Whole grains have been front and center in dietary guidelines for decades now. Epidemiology studies have long found that whole grains and dietary fiber correlate with health benefits such as better glycemic control, better insulin sensitivity, less heart disease, and less weight gain.

Now, two new studies in the American Journal of Clinical Nutrition offer experimental evidence to support those links. In a six-week randomized trial, J. Philip Karl and colleagues compared the effects of whole grains and refined grains on metabolic function. They found that people consuming whole grains for six weeks burned more energy and absorbed fewer calories from their food.

The result was 92 fewer calories per day retained – and potentially stored as fat – by people eating whole grains. Hunger, fullness, and diet satisfaction were no different between the two groups. Some indications of a trend toward better glucose tolerance in the whole grain group fell short of statistical significance.

Data from the same subjects in a second paper show modest favorable effects on gut microbiota, and on markers of immune function and inflammation. It’s reassuring to have this new evidence, says Karl:

Many previous studies have suggested benefits of whole grains and dietary fiber on chronic disease risk. This study helps to quantify how whole grains and fiber work to benefit weight management, and lend credibility to previously reported associations between increased whole grains and fiber consumption, lower body weight and better health.

“Wheat Belly” entrepreneurs have been doing their best to cast aspersions upon eating many whole grain foods. Seeing these new data is a breath of fresh science.

Click here for study on energy balance and here for the study on microbiota. For further perspective, click here.

Whole Grain Sandwich Loaf, photograph © Mike McCune / flickr

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February 12, 2017