Researchers found that replacing carbs like potatoes and rice with lentils lowered study participants’ post-meal blood sugar levels significantly. While that may not sound that exciting, “postprandial blood glucose” is a measurement with implications for both long-term health and day-to-day healthy eating challenges like overeating and energy.
Here’s what you need to know.
Blood Sugar Background
Every time you eat, your blood sugar rises. How high it rises and how long it stays there largely depends on what kind of food you eat. Simple, refined carbohydrates (think sweets and refined grains like white bread and white rice) require less digestion than their whole, complex counterparts (think whole grains, legumes, and vegetables). Therefore, they hit your bloodstream very quickly, sending your body up the steepest hill on a blood sugar roller coaster.
While that may sound fun to thrill seekers, your body wants to keep your blood sugar stabilized, and the quick rising and subsequent falling of your blood glucose levels will leave you feeling tired and hungry shortly after eating. Short-term side effects of this could be overeating and lack of energy.
If this process is repeated often over time (for instance, if most of your diet comes from refined carbohydrates without fiber to slow down the digestive process), it can lead to things like insulin resistance, obesity, and diabetes.
The Research Details
Foods that reduce those spikes and keep things stable and smooth, then, are super beneficial.
To see how lentils would fare in that realm, researchers fed 24 healthy adult subjects four dishes: one with white rice only and the other three with half the amount of white rice paired with three different varieties of lentils. They then repeated the process with white potatoes instead of white rice.
The results: When half of the rice was substituted for lentils, researchers found a 20 percent reduction in participants’ blood glucose levels. When half of the potatoes were substituted for lentils, participants’ blood glucose levels dropped by a whopping 35 percent.
Each of the three types of lentils tested showed similar results, suggesting that other pulses (like chickpeas) might provide similar benefits.
What This Means for Your Healthy Diet
We’d just as soon eat all lentils and skip white rice altogether, but the researchers believed that by combining them with rice or potatoes they could more accurately reflect an average meal, as lentils (and other pulses) are typically consumed in combination with other starches.
So if you have trouble totally giving up white rice and potatoes in favor of more nutrient-dense counterparts, this research highlights an easy way to significantly reduce the negative effects consuming these foods can have on your body without giving them up completely.
While this was a very small study, we already know lentils—and legumes overall—are a nutrient-dense food worth adding to your diet, and this just adds another line to the long list of health benefits.
It also highlights the fact that in order to make positive changes to your health, you don’t have to completely change overnight. Making adjustments as small as substituting half of your usual portion of a less healthy food with a more nutrient-dense one can have a real impact and is a great step in working towards a larger goal.