Research Finds This Food Could Lead To A Smaller Waist Size

Carbohydrates are a hot topic for many diets. While many diets advocate for cutting carbs, new research says carbohydrates — specifically whole grains — can actually promote weight loss.

In a July 2021 study published in the Journal of Nutrition, researchers from Tufts University found that adults who followed the 2020-2025 Dietary Guidelines for Americans' recommendations of three or more servings of whole grains a day had smaller increases in their waist size, as well as smaller increases in their blood pressure and blood sugar. The findings were compared to adults in the same age group — an average age of mid-50s — who ate less than a half serving of whole grains a day (via Tufts University).

Researchers analyzed data from 3,100 participants over the course of 18 years on how whole grain and refined grain intake affected their blood pressure, blood sugar, HDL ("good") cholesterol, triglycerides, and waist size. The study findings showed that the participants who had a high-intake of whole grains had only a ½ inch waist size increase on average, while the low-intake population experienced a waist size increase by over 1 inch, according to Tufts University. Participants who consumed a low amount of whole grains also experienced a greater average increase in blood sugar and systolic blood pressure.

The study also investigated refined grain intake specifically, with researchers finding that participants who consumed a lower amount of refined grains had a lesser average increase in waist size, as well as a decline in triglycerides. Researchers said the findings show that whole grains are a necessary part of a healthy diet and also help people maintain the health benefits over time. "These data suggest that people who eat more whole grains are better able to maintain their blood sugar and blood pressure over time. Managing these risk factors as we age may help to protect against heart disease," said Nicola McKeown, senior and corresponding author, in a news release. 

You may be wondering about the difference between whole grains and refined grains. Whole grains — like brown rice, rolled oats, and whole-wheat bread — are less processed than refined grains. They still contain fiber and vitamins because they haven't been milled out, which leaves starchy refined grains like white pasta or white bread (via Tufts University).

"The presence of dietary fiber in whole grains can have a satiating effect, and the magnesium, potassium, and antioxidants may contribute to lowering blood pressure. Soluble fiber in particular may have a beneficial effect on post-meal blood sugar spikes," research team member Caleigh Sawicki told Tufts University.