Food Order Matters: Eat Carbs Last For Better Blood Glucose, Study Says

Prediabetes? Eating protein or protein and veggies before carbs may even out your blood sugar levels, researchers find.

Eat Carbs Last for Better Blood  SugarEating protein first and saving carbs for last may benefit your blood glucose levels and help cut down on your overall carb consumption, too.

When a diagnosis of prediabetes happens, many people have the same reaction: Oh no! No more carbs! How could I live without my favorite chips, bread, cookies?

While your doctor may indeed suggest cutting back on carbs, new research suggests that another approach—a simple measure—may also help your blood glucose levels.
In basic terms: Don't eat your carbs first at a meal. Hold that bread basket, waiter.

Eating foods containing protein or consuming non-starchy vegetables, or both, before carb-containing foods can stabilize blood glucose levels right after a meal, according to study lead author Alpana Shukla, MD, MRCP, assistant professor of research and director of clinical research at the Comprehensive Weight Loss Center, Weill-Cornell Medicine in New York City.

One word of caution—not all carbs, or vegetables are created equally. "Vegetables contain carbohydrates and some will impact the blood sugar more than others," explains Jodi Godfrey, MS, RD, and editor EndocrineWeb. "Carbohydrates that come from non-starchy vegetables—such as kale, other greens, broccoli, and cauliflower—are absorbed more slowly and require less insulin than vegetables with more starch such as corn and potatoes." Other foods that contain sugar and are made from processed white flour (pasta, bread, cereals) have more carbs and require more insulin as a result.

About the Study
Dr. Shukla and her colleagues assigned 15 patients with prediabetes to eat three identical meals on three different occasions. Each time, they ate carbohydrate, protein, and vegetables in a different order. The researchers took blood samples to measure glucose and insulin at the start of each session and then 6 more times over the next 3 hours.

"The after-meal glucose spikes are reduced by over 40% when patients started the meal with vegetables or vegetables plus protein," Dr. Shukla says, compared with starting with carbohydrate-laden foods such as bread. "When you start a meal with carbohydrates, glucose levels peak and then dip dramatically," she says.

That is because when you eat the carbs first, ''you stimulate a much bigger insulin response'' than is stimulated with vegetables or foods high in protein, she says. Next, the blood sugar declines too much.

More Study Details

While research already has found that the nutrient order affects post-meal glucose and insulin levels in those with type 2 diabetes, research is lacking on the idea in those with prediabetes, Dr. Shukla says.

The 15 men and women in her study were on average 52 years old. Their average BMI was 34, or obese. They were all diagnosed with prediabetes. The researchers used the standard definition—an A1C of 5.7 to 6.4%.

"The only thing they did differently was the order," Dr. Shukla says of the three sessions. "Each time they ate the exact same meal, gram for gram, carb for carb."
Each meal was eaten in 30 minutes. Each person ate the meals three different ways on three different occasions, with a 10-minute rest between courses:

  • Carbohydrate (ciabatta bread) first, then protein (skinless grilled chicken breast) and vegetables (lettuce, tomatoes, bell peppers, red cabbage, with balsamic vinegar and olive oil).
  • Protein and vegetables first and then carbs.
  • Vegetables first, then protein and carb together.

The vegetables first triggered the least insulin response, the researchers found. All participants had similar blood glucose readings at the start.

Bottom line: Skip the bread basket until you eat your proteins and vegetables, Dr. Shukla says.

While it's wise to cut back on carbs, she acknowledges that it is difficult for many people. This alternative strategy is often welcomed by patients, she says. Her own patients have found it useful and ''we have seen some long-term effect on the A1C," she says. Those findings so far are anecdotal, but she plans next to do another research study to document scientifically the long-term effects of this approach.

Expert Perspective

The idea is a good one,  says Caroline Apovian, MD, FACP, FACN, professor of medicine and pediatrics, Boston University School of Medicine, and president of The Obesity Society. She is on the editorial board of OnTrack Diabetes.

"I think in other countries they do this already," she says. It's easily adapted here by simply eating salad first. However, she says, ''it's the exact opposite of what Americans do in restaurants." We have the ''bread basket mentality."

One limitation is the small number of study participants, Dr. Apovian says. Even so, any measures to help prevent or delay prediabetes from becoming diabetes are welcome, she says.

"If you are reducing the amount of insulin [released after a meal], you are sparing the beta cell, protecting the beta cell from developing full-blown diabetes. If you have the protein and vegetables in your stomach and then you have the bread, there is a slowed carbohydrate absorption due to the effect of the fiber and the fat," she explains.

The carbs-last model may actually help you cut down on carbs, she suspects. "It's very likely if you eat the protein and vegetables first you will be less likely to be hungry for lots of bread."

Dr. Shukla has no disclosures. Dr. Apovian has no disclosures.

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