Is Correcting Low Blood Sugars Caused by Exercise Making You Fat?

Over the years, I have had many exercisers with diabetes ask me why they’re gaining weight instead of losing it. There are two possible answers to that question. One answer is that muscle is heavier than fat, so if you are gaining muscle while losing fat-especially in the early stages of a new exercise program-your scale weight probably doesn’t reflect your positive changes in body composition (i.e., less fat, more muscle).

The second possible answer is more applicable to people who are not new to exercise, but who may have recently changed the amount or intensity of their training. I always ask them, “Have you been treating a lot of low blood sugars recently?” When they invariably reply, “Yes,” then I know to tell them that they have simply been taking in too many extra calories while treating hypoglycemia.

Of course, you have to treat a low if you have one! However, every calorie counts, even those  that boost your blood sugar back to normal (and beyond). People with diabetes often reach for candy, cola, juice, or other high calorie, high fat, and high sodium foods to correct lows, which can lead rebound high blood sugars, unhealthy eating, and weight gain. What you use to correct a low is usually just extra calories not accounted for in your daily meal plan.

What can you do to avoid gaining weight when you have to treat lows, especially if you have them fairly often?  The best advice is to treat them with something low in calories that has enough glucose to bring your sugars back to normal. When you have a hypoglycemic reaction, do not binge on candy, cookies, and other high calorie, high fat foods. These “treats” take longer to raise your blood sugar than pure glucose and usually contain calories (like those from fat) that do not raise blood sugar levels effectively. You are almost certain to eat too much of them while waiting for your blood sugar to rise, and you end up consuming unnecessary calories that cause weight gain. Excess weight gain can lower the ability of your insulin to keep blood sugars in check. You can also end up with rebound hyperglycemia, which may increase your insulin needs and promote fat storage.

I’m going to sound like a walking advertisement for glucose products from here on out, but both professional and personal experience has taught me how critical it is to make smart choices when you want to exercise regularly and avoid weight gain. Using fast-acting glucose to raise your blood sugars is likely to contribute the fewest extra calories. Why? Pure glucose tablets contain only four calories per gram, so a 15-to-20 gram treatment has 60 to 80 calories, and every single calorie goes directly to rapidly correcting your blood sugar levels.

Hypothetically speaking, if you’re correcting just two lows per week with 15 grams of carbs, you will take in an extra 6,240 calories a year, or the equivalent of almost two pounds of body fat (one pound of fat is 3,500 calories). By way of comparison, getting 15 grams of carbs from other foods usually results in the consumption of far more calories, especially if any of the foods contain fat (nine calories per gram) or protein (four calories per gram), neither of which will rapidly correct a low blood sugar.

Here are a few other food comparisons:

●   A two-ounce bag of Skittles candy contains almost 60 grams of carbohydrate and four times the calories of a 15-gram glucose dose. Likewise, just one ounce of Smarties contain 25 grams, which would probably raise your blood sugar too much and cause you to take in extra calories.

●   A candy bar like Snickers contains about 100 extra calories for every 15 grams of carbs. Correcting lows with Snickers or other candy bars adds another three-pound weight gain a year.

●   A regular soda that contains high-fructose corn syrup may take longer to correct a low (fructose has to be converted into glucose first),  and it’s easy to consume more than 15 grams-which is the amount in only four ounces of a soda (one-third of a 12-ounce can).

●   Even choosing orange juice or a banana to correct a low is less effective because the fructose (fruit sugar) is much more slowly converted into glucose. You probably won’t be able to stick to only four ounces of juice or half of a medium banana (15 grams of carbs) while you wait for your low to be corrected, and you may end up consuming more calories than necessary.

Check out some calorie intake comparisons using Dex4’s new Hypo Smart Choice Calculator at You’ll probably be surprised by how many extra calories you may be consuming just by treating low blood sugars with the usual treatments like orange juice and soda!

There is nothing worse than exercising and trying hard to lose weight, but ending up gaining instead due to all the extra calories you consume when correcting low blood sugars. If you can prevent exercise-related low blood sugars with diet and medication changes and thereby avoid taking in those extra calories in the first place, certainly do that!  But when you do have to treat an occasional low, keep in mind that using food rather than pure glucose can add a lot of calories to your total yearly intake, and your lows may take longer to correct.

In short, pure glucose is always best for rapid treatment of lows. For prevention of lows during longer bouts of exercise or overnight, however, consider taking in a low-calorie bedtime snack with a balance of carbs, protein, and fat, which will keep your blood sugars stable for longer. Some examples are Balance bars, low-fat and reduced sugar yogurt, or low-calorie ice cream. An ounce of prevention is always worth a pound of cure, especially if a hypoglycemic episode leads you to eat everything in sight!


Sign up for five free healthy living reports via e-mail or receive very low-cost weekly “Fit Brain, Fit Body!” fitness/lifestyle programs at Access more articles and information at If you need tips for getting safely started on an exercise program, check out The 7 Step Diabetes Fitness Plan.  For people with any type of diabetes who are already active, consult the Diabetic Athlete’s Handbook.



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