Whole Grains and Weight Loss: What the Research Says

Mixed messages on whole grains have left many people confused about what to eat. Although the benefits of fiber are widely accepted, do whole grains have too many carbohydrates to fit into a healthy eating plan? How about for weight loss? Here's what the research has to say.

Whole Grains vs. Refined Grains

Understanding the difference between whole grains and refined grains is the first step to making sense of the studies. Whole grains retain all of their original components. In fact, they need to have all three parts to be considered a whole grain. For example, whole-grain wheat contains the endosperm, bran (the high-fiber outer layer) and the germ (which is rich in vitamin E). Refined grains, on the other hand, have been stripped of these nutritious layers, making them higher in simple starch and generally lower in fiber and other key nutrients.

Examples of whole grains include quinoa, oatmeal, whole wheat flour, popcorn, and brown rice. And grains like freekeh, wheatberries, and farro are whole grains that have become more popular in recent years. Enriched flour, white rice, and white bread are examples of refined grains.

The Difference Between Whole and Refined Grains

What the Research Says

The National Health and Nutrition Examination Survey (NHANES) collects large-scale data on food patterns in children and adults across the United States. Upon examining NHANES data, researchers found that consuming whole grains instead of refined grains significantly improved intakes of fiber and other beneficial nutrients.

Furthermore, both children and adults who meet the recommendations for whole-grain intake are shown to have a lower body mass index (BMI), reduced likelihood of overweight and obesity, and smaller waist circumferences. However, it is important to keep portion size in mind.

Even though grains are a healthy food choice, overeating them can lead to weight gain. A single serving of whole grain bread is one slice. If you consume whole grain cereal, 1/2-3/4 cups is a single serving. And when eating rice or pasta about 1/2 cup is a single serving.

Replacing refined grains with whole grains also appears to offer health benefits beyond weight loss. A 2012 study placed 79 overweight and obese postmenopausal women into two different groups. Both groups were on a calorie-restricted diet, but one was eating whole grains and the other consumed refined grains. Although both groups lost the same amount of weight, the whole-grain group had a greater decrease in their percentage of fat mass. Furthermore, the refined grain group had an increase in LDL (bad cholesterol). Aside from weight loss, whole grains show positive effects on body composition.

A large review of research on whole grains confirms this observation. There seems to be a consensus that replacing refined grains with whole grains leads to a decrease in body fat, even when body weight stays the same. This points out an important angle to consider when evaluating health based on body weight alone. The number on the scale doesn't tell the whole story. Choosing whole grains over refined grains could lead to internal body changes, such as fat loss, which impact more than just weight. Lower body fat mass and lower LDL cholesterol are both beneficial changes for heart health.

You May Be Eating More Grains Than You Think

Adding in Whole Grains

If you don't eat grains currently, adding whole grains to your meal plan can be a beneficial way to boost your total fiber intake. Fiber has well-documented benefits for weight loss. By increasing satiety and assisting with digestion, fiber plays an important role in sustainable weight loss. Unless you have been diagnosed with a health condition that restricts your grain intake (or if you have decided to adopt a lower carbohydrate eating plan for personal reasons), there is no reason to exclude grains from your eating plan. The key to eating grains is choosing the right kind of grain and the appropriate portion size.

Here are some ideas to integrate more whole grains (and fiber) into your life:

• Have a serving of whole-grain oatmeal for breakfast. Choose steel-cut oats or old-fashioned oats without added sugar to get maximum nutrition out of your whole-grain breakfast. Add a serving of berries and some chopped nuts for a complete breakfast. Or to make a single serving go further, try cooking them "growing oatmeal" style.
• Snack on whole-grain crackers. Look for whole-grain crackers with simple ingredients and lots of fiber. Pile them up with veggies, avocado, nut butter, or hummus. For a high-protein sandwich substitute, add tomato slices, yellow mustard, and turkey slices. Keep in mind that a single-serving of crackers is usually about four crackers.
• Wrap a whole-grain flatbread around your sandwich fixings. Instead of white bread or fluffy rolls, a whole-grain wrap or flatbread will keep you full for longer. Be sure to check the Ingredient's List on the food label for the words "whole grain."
• Use whole-grain cereal to "faux-fry" your favorite foods. Experiment with a clever kitchen hack by trading white flour and hot oil for high-fiber cereal and eggs. Create crunchy "fried chicken” the healthy way.

Great Whole Grains to Add to Your Diet

A Word From Verywell

Everyone is a little bit different when it comes to striking an ideal balance of carbohydrates. If you're looking to make a healthy change, simply switch out refined carbohydrates for their less processed whole-grain counterparts. This is a great place to start that offers proven benefits. Experiment with natural foods you enjoy to find the right menu to fuel your body.