Which foods were participants in the research instructed to consume — or avoid?This randomized clinical study involved 150 older persons with untreated prediabetes or less severe diabetes, which is considered the gold standard in scientific research. All were obese (average BMI 35), with approximately three-quarters being women and 59% being Black. Over the course of six months, half of the participants were randomly allocated to a low-carb diet with periodic nutritional counseling, while the other half ate their normal diet. Low-carb participants were required to maintain carbohydrate levels below 40 grams per day for the first three months — about the amount of carbohydrates in an English muffin and an apple. During months four through six, their carbohydrate restriction was less than 60 grams per day. Participants should consume non-starchy vegetables, fish, poultry, lean meat, eggs, olive oil, avocados, nuts and seeds, Greek yogurt, low-carb milk, and modest quantities of cheese, according to the researchers. Other dairy, fruits, legumes, beans, and grains were suggested to be limited or avoided. Throughout the trial, the low-carb individuals were given a variety of items, including olive oil, green beans, tomatoes, tuna, non-sugar sweeteners, almonds, and low-carb snacks and drinks.
What did the research discover?Three and six months into the experiment, all participants had blood tests. Participants who followed a low-carb diet improved their A1C and fasting blood glucose levels more than those who followed a standard diet after six months. They also shed 13 pounds on average. Despite being modest, the A1C improvements reflected a roughly 60% reduction in the chance of acquiring diabetes over the following three years. "The drop in A1C was larger in white individuals compared to black participants, which is essential to note," Dr. Romeo explains. "The research helps us understand if the reaction to a low-carb diet is equivalent across races by adding a large number of Black people. It does not seem to be in this experiment."
Was the low-carb diet the sole element that contributed to improved blood sugar control?No. Dr. Romeo says it's hard to know how much weight reduction among low-carb individuals contributed to improved blood sugar management. Losing fat aids in the reduction of insulin resistance. "That implies your body will react to the action of the insulin you produce more efficiently," he explains. "That is certainly extremely beneficial."
However, he believes that two direct impacts of the low-carb strategy may also be to blame for the blood glucose fluctuation. Making your body depend on sources of energy other than carbs reduces your hunger. Furthermore, when you consume more carbohydrates, your pancreas must create more insulin. Eating fewer carbohydrates decreases the pancreas' workload and improves insulin resistance independently of weight reduction.
Other research limitations, such as the comprehensive dietary counseling provided to low-carb groups and self-reporting of daily meals, may have biased outcomes. Dr. Romeo also mentioned that the research was neither big nor long-term, both of which would have bolstered its conclusions. "It doesn't necessarily address how durable this low-carb diet is," he adds, adding that a 12-month or 18-month trial would be beneficial. "However, I believe it is a significant step in that direction."
Can a sensible approach to carbohydrates make a difference?Not everyone with prediabetes will be willing or able to reduce their carbohydrate consumption to the severe levels used in the research. However, reducing even a little amount of carbohydrates may result in blood sugar and weight management advantages, according to Dr. Romeo.
"The rather high carbohydrate consumption that we've all been used to — bread, sweets, starchy veggies — may be dialed down a little," he adds. "Not only does this lower the risk of diabetes, but it may also aid in weight reduction."