Are You Carbohydrate Intolerant? Here's How To Know + What To Do About It

Carbohydrate tolerance is a gray area. The amount of carbohydrates that works for one person's metabolism doesn't always serve another's. In the past decade, I've seen a growing number of patients who for years have limited sugary foods and swapped out refined carbohydrates for whole grain products, sweet potatoes, and fresh fruit. Yet they are overweight or have surges of fatigue, foggy-headedness, or cravings. Sometimes they don’t carry any extra pounds but have worryingly high levels of blood sugar. It’s not unusual for these issues to come on late in life; their response to a diet they used to do well on has suddenly shifted.

Why this happens is a topic of robust debate in nutritional circles. It’s likely a combination of factors: a genetic predisposition combined with a sedentary, stressful, and sleep-deprived lifestyle; decades of processed foods and medications that have altered the microbiome; or even (unfortunately) overconsuming the healthy-seeming multigrain breads, bananas, and beans, which all turn to sugar in the blood. All this can lower your personal "set point" for tolerating carbohydrates so that your blood sugars don’t fall back to normal within two hours of eating as they should. Instead, they stay elevated, going beyond what the cells can handle, and eventually this triggers a chain of effects that lead to insulin resistance, the precursor to high blood pressure, heart disease, diabetes, obesity, possibly Alzheimer’s disease, and even some cancers. The 2017 National Diabetes Statistics report found that an estimated 50 percent of Americans have either diabetes or pre-diabetes and that many are unaware of this fact.

Taking your blood sugar seriously is nothing to sneeze at. When carb intolerance is at play, your body is telling you to get stricter with your intake. To follow a low-carb diet, nix all sugars and reduce complex carbs dramatically, replacing them with plenty of nonstarchy vegetables and generous amounts of fat. In addition, take sleep seriously, work on repairing the gut, and increase the amount of movement you do. The low-carb diet, along with these other fundamental improvements, can often help restore order where there was previously metabolic chaos. To catalyze real metabolic change in cases of significant weight gain or diabetes, it may be warranted to take the low-carb approach to its ultimate extreme: the ketogenic protocol.

Take heart! Healthy low-carb diets can improve blood pressure and help you lose weight, have fewer sugar cravings, and feel less driven by hunger. Skin and digestion often improve, as well as triglycerides (a form of blood lipids) and blood sugar and insulin markers.

Your tolerance can rise and fall depending on how much you exercised, how well you slept, how stressed you are, and so on. There’s nothing a doctor can give you that is more valuable than this personal awareness. If you find that you handle whole-food complex carbs quite well, I still advise that you keep them to a reasonable amount, picking from the low- and medium-count foods described above. If you are using carb-counting devices, know this: Conventional dietary recommendations suggest a limit of 225 grams per day. That’s too high: Stay under 150 grams a day maximum, and preferably under 100 grams.