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Another problem with high blood sugar: It undermines aerobic exercise

“The interindividual variability in glycemic responses to standardized meals also highlights the personal nature of glucose regulation.”

While you might be saying, “Huh?” right now, I’m saying, “Right on.” That medical mumbo jumbo from Stanford University researchers in a July 2018 PLOS Biology article staunchly supports the advice I often offer to you about optimal eating.

To be both scientist and subject and experiment, experiment, experiment with your meals.

And if you mentally machete your way through the rest of the article’s jungle of jargon, you’ll find even more proof of what I dubbed the Snowflake Theory of Dieting 35 years ago. That our ways of digesting and assimilating foods are as unique as snowflakes, so if you and I eat the same meal at the same time under the same conditions, it will affect our bodies, including our blood sugar levels, somewhat differently.

While the Snowflake Theory of Dieting was pure speculation initially (and many certified nutritionists would’ve certainly scoffed at it in the 1980s), Stanford researchers came to that same conclusion 30-plus years later by testing 57 diabetes-free adults extensively and then feeding them three different breakfasts: cornflakes with milk, bread with peanut butter, and a protein bar. But their study revealed something I never suspected way back when.

The Snowflake Theory, I reasoned, is why you might not lose as much weight - or any at all! - on the same diet that produced a 10-pound weight loss in me. I never imagined, however, that our ways of digesting and assimilating foods are so different that a breakfast of cornflakes and milk produced such “severe glucose variability” that 45 of 57 subjects in the Stanford study recorded blood sugar levels so high as to indicate they are prediabetic.

In fact, this research even detected “severe glucose variability” 25 percent of the time in the subgroup of subjects found to have the most normal blood-sugar reactions to meals.

The need for this research is clearly stated in the article’s introduction. Besides the fact that almost 30 million people in the United States are already diabetic, “another 84 million are prediabetic, and without intervention, up to 70 percent of these individuals may progress to type 2 diabetes.”

Prior to this study, the strategy for keeping prediabetes at bay was to exercise sufficiently and eat in a way that keeps your blood sugar level as constant as possible. But if there can be “severe glucose variability” in people who usually react normally to meals, how can you be sure that meals you judge to be healthy are actually healthy for you?

This problem previously surfaced in research published in 2016 by the American Journal of Clinical Nutrition that questioned the validity of the glycemic index, a measure represented by a number from 1 to 100 of how 50 grams of an individual food affects blood glucose. The GI is often used by diabetics and dieters to make food selections.

Led by Nirupa Matthan, the paper concluded “these data indicate that there is substantial variability in individual responses to GI value determinations, demonstrating that it is unlikely to be a good approach to guiding food choices.” The paper ended this way for good reason.

According to the Harvard Health Publishing website, white bread scores a 75 on the GI with 2-point margin for error. Yet when Matthan and his colleagues tested 63 healthy volunteers, the scores ranged between 35 and 103.

Moreover, the research found that the GI scores changed 20 percent of the time when the same person ate the same food at a later date.

Despite the gloom and doom in these two studies, there is a way to take the guesswork out of your diet: Be both scientist and subject and experiment, experiment, experiment with your meals. Keep an open mind and use the following nutritional nugget as your North Star.

Protein and complex carbohydrates temper the insulin response. If you make sure any experimental meals feature these two macronutrients, high blood sugar should not be an issue.

And keeping your blood sugar at its proper level does more than help you keep a healthy weight and reduce your odds of type 2 diabetes. Very recent research with mice and human subjects show that higher than normal levels of blood sugar adversely affect aerobic exercise.

Research performed at Harvard University and published this summer in Nature Metabolism found that when mice were fed one of two diets designed to induce high blood sugar and then ran on a treadmill, their efforts produced no improvement in aerobic fitness. Specifically, their muscle fibers did not become more efficient at using oxygen nor did they grow new blood vessels.

When doing follow-up work with human subjects, the researchers found that those with impaired glucose intolerance - a condition where blood sugar levels rise excessively with the consumption of glucose - experienced less aerobic improvement when compared to those who did not have impaired glucose intolerance and did the same workouts.