Time to go against the grain?
The debate over “good versus bad carbs” has long tormented diners — now, new research published in Frontiers in Nutrition is revealing the carbohydrates you should be choosing at mealtime.
“It’s tempting to think of all carbohydrate foods as interchangeable,” study author Keith Ayoob, associate professor emeritus at Albert Einstein College of Medicine in the Bronx, said in a statement.
“But these foods are categorized within different food groups for a reason — perhaps most importantly, they tend to have vastly different vitamin and mineral contents.”
His study found that replacing starchy vegetables like potatoes with grain-based foods like rice and whole-grain bread for just one day led to a drop in potassium by 21%, vitamin B6 by 17%, vitamin C by 11%, and fiber by 10%.
Ayoob created two one-day menu models: one focused on starchy vegetables (serving hash browns at breakfast and a baked potato at dinner) and one with grains (replacing the potatoes with whole wheat bread at breakfast and white rice at dinner).
Compared with starchy vegetables, grains tend to be lower in potassium and vitamin C, but provide higher amounts of thiamine, zinc, and vitamin E, Ayoob noted in his findings.
“Many starchy vegetables are good sources of potassium (e.g., one medium potato provides 15% [daily value]). Consuming grains in place of starchy vegetables may further widen the gap between recommended and actual intakes of potassium,” he wrote.
“A meaningful decrease in fiber intake (−10%) also occurred when grains replaced potatoes. This finding reinforces the need to include both starchy vegetables and grains in the diet.”
The Dietary Guidelines for Americans recommend most adults consume 5 cups of starchy vegetables each week.
Starchy vegetables:
- Breadfruit
- Burdock root
- Cassava
- Corn
- Jicama
- Lima beans
- Lotus root
- Plantains
- Salsify
- Tapioca
- Turnips
- Water chestnuts
- White potatoes
- Yams
- Yucca
Ayoob outlined his study’s limitations — potatoes were the only starchy vegetable incorporated into the menu modeling, which covered just one day.
Modeling done with other starchy vegetables, and over 7 days or more, may yield different results.
He pointed out that starchy vegetables have nutrient profiles that are distinct from those of grain foods — which should be recognized in dietary guidance.
“As is so often the case in the world of nutrition, guidance comes down to balance, variety and moderation — which might sound boring, but all three would benefit most people’s eating styles,” he emphasized.
“It’s important to get the right mix of vegetables and grains and include both starchy and non-starchy vegetables to help ensure we’re meeting both our macronutrient and micronutrient needs.”