The fastest way to raise blood sugar is to eat or drink 15 grams of simple carbohydrates, then wait 15 minutes and recheck. This approach, known as the 15-15 rule, is the standard method for treating blood sugar that drops below 70 mg/dL. The key is choosing the right type of carbohydrate, because not all foods work equally fast.
The 15-15 Rule
When your blood sugar drops below 70 mg/dL, eat 15 grams of fast-acting carbohydrates. Wait 15 minutes, then check your blood sugar again. If it’s still under 70 mg/dL, repeat with another 15 grams. Keep repeating until you’re back in your target range, which for most people is 80 to 130 mg/dL before a meal.
The reason for the structured approach is that it prevents you from panic-eating your way through the kitchen. Overtreatment is one of the most common mistakes. When blood sugar crashes, the urge to keep eating until you feel better is strong, but glucose takes about 15 minutes to hit your bloodstream. If you eat 45 grams of carbs in one sitting because you still feel shaky, you’ll likely end up with blood sugar that swings too high afterward. That rebound spike is hard on your body over time, contributing to higher average blood sugar levels and greater variability throughout the day.
Best Fast-Acting Foods
Simple carbohydrates digest quickly and cause a rapid rise in blood sugar. That’s normally a drawback, but when you’re low, it’s exactly what you need. The best options to get 15 grams of fast-acting carbs include:
- Glucose tablets: 3 tablets (the most precise option, available at any pharmacy)
- Fruit juice: half a cup (4 ounces)
- Regular soda: half a cup (4 ounces), not diet
- Hard candies: check the label for the right count to reach 15 grams
- A tablespoon of honey or sugar dissolved in water
Glucose tablets are the gold standard because they contain a precise amount of sugar and nothing else. Juice and regular soda work almost as well and are easier to find in most kitchens. The common thread is that all of these are pure or nearly pure simple sugar with minimal fat, fiber, or protein slowing things down.
Why Some Foods Don’t Work Fast Enough
Chocolate bars, peanut butter crackers, and other snacks that combine sugar with fat or protein are poor choices when you need speed. Fat slows down how quickly your stomach empties its contents into the small intestine, where sugar actually gets absorbed. When researchers added fat to a carbohydrate meal, the glucose response was noticeably blunted and delayed, likely because the fat held everything in the stomach longer.
Complex carbohydrates like whole grain bread or oatmeal also take longer to break down. Your body has to disassemble the longer starch chains into individual sugar molecules before they can enter the bloodstream. Simple carbs skip most of that processing, which is why juice raises blood sugar in minutes while a bowl of brown rice takes much longer. Save the complex carbs for after you’ve stabilized.
Stabilizing After the Initial Fix
Once your blood sugar is back above 70 mg/dL, the job isn’t done. A few glucose tablets or a splash of juice will wear off relatively quickly, and if your next meal is more than an hour away, your blood sugar can drop again. Eating a small snack that includes protein and complex carbohydrates, like cheese and whole grain crackers or a handful of nuts with a piece of fruit, helps keep your levels steady over the next few hours.
If you’re using insulin or certain diabetes medications, think about what caused the low in the first place. A skipped meal, an unusually intense workout, or a medication timing issue are common triggers. Identifying the pattern can help you prevent the next episode.
Dosing for Children
Children need less sugar to correct a low. The general guideline is about 0.3 grams of fast-acting carbohydrate per kilogram of body weight. In practice, that works out to roughly 9 grams for a child who weighs about 66 pounds (30 kg) and 15 grams for a child around 110 pounds (50 kg). At those doses, blood sugar typically rises by about 55 to 70 mg/dL within 15 minutes without causing a rebound spike before the next meal. Glucose tablets can be broken in half for smaller children, and a few ounces of juice works well for kids who resist tablets.
When Someone Can’t Eat or Drink
Severe hypoglycemia is a different situation. If someone is confused, having a seizure, or unconscious, do not try to put food or liquid in their mouth. They could choke. This is when glucagon becomes essential.
Glucagon is a hormone that signals the liver to release its stored sugar into the bloodstream. It’s available as a nasal spray and as an injectable kit, both by prescription. The nasal spray delivers a single 3 mg dose into one nostril and doesn’t require any mixing or priming. If there’s no response after 15 minutes, a second dose can be given. After administering glucagon, call emergency services immediately.
If you take insulin or medications that can cause lows, having a glucagon kit at home and making sure the people around you know where it is and how to use it is one of the most important safety steps you can take. The nasal version is simple enough that a coworker, teacher, or family member can administer it with no medical training.
Avoiding the Overtreatment Trap
The body has its own emergency backup system for low blood sugar. When levels drop too far, your body releases adrenaline, cortisol, growth hormone, and its own glucagon to trigger a glucose dump from the liver. This is why you feel shaky, sweaty, and anxious during a low: those are adrenaline symptoms, not just sugar symptoms. If you pile a large amount of carbohydrates on top of this hormonal response, your blood sugar can rocket well past your target range.
Repeated high spikes after lows contribute to higher average blood sugar over time. This shows up as a higher A1C, the test that reflects your average blood sugar over three months. Sticking to the 15-15 rule, even when every instinct tells you to eat more, is the best way to correct a low without creating a new problem on the other side.