Why Blood Sugar Rises Twice After Pizza, Pasta and Potatoes in Type 1 Diabetes
If you’re raising a child or teen with Type 1 Diabetes, you may have noticed something strange after certain meals. Pizza, pasta, potatoes…sometimes their blood glucose looks fine at first, then hours later-boom!- it rises again. That’s what many families call the “double spike.” But why does it happen, and what can you do about it? Let’s break it down.
The Science Behind the Double Spike
Carbohydrates are the body’s main source of energy, and they’re the first thing we look at when carb counting. But pizza, pasta and potatoes come with a twist: they’re often mixed with lots of fat and protein.
Here’s what’s going on:
First spike: The carbs (like the pasta or potato) start digesting quickly, raising blood sugar within an hour or two.
Delayed spike: Fat and protein slow down digestion. That means more carbs are absorbed later- sometimes 3-5 hours after eating. Add in the fat from cheese on pizza or creamy sauces with pasta, and suddenly blood sugar rises again long after the meal is over.
It’s like the carbs are sneaky- part of them show up early, and the rest arrive fashionably late.
Foods Most Likely to Cause a Double Spike
Pizza (carbs from the base, fat from cheese and toppings)
Pasta with creamy or meaty sauces
Potatoes cooked with oil or butter (chips, roasties or mash)
Takeaway meals (often high in both carbs and fat)
Not all carbs are equal! A bowl of plain rice or fruit usually won’t cause the same delayed rise because there isn’t much fat slowing digestion down.
Tips to Tackle the Double Spike
Managing these meals isn’t about avoiding them- children and teens should still enjoy their favourites! It’s about learning some tricks to keep blood sugar steadier:
1. Timing of Insulin
Sometimes giving part of the insulin dose before eating and part later can help match digestion. This is often called a split bolus (or dual/extended bolus if using a pump). Always check with your diabetes team before trying new strategies.
2. Use Tech to Your Advantage
If your child uses a pump, extended bolus settings can spread insulin over several hours to better match slow digestion. For injections, some families do a small correction dose later.
3. Pair with Veggies or Lean Protein
Adding fibre-rich veggies or lean protein can help slow digestion in a more predictable way, making blood sugar less “rollercoastery.”
4. Keep an Eye on Portions
Bigger portions= more carbs + more fat = bigger spikes. Teaching teens to balance pizza with a side salad or having one slice less can make a big difference.
5. Watch the Timing
Check blood glucose (or CGM trends) at different intervals after these meals- 1 hour, 3 hours, 5 hours. Patterns will start to show, helping you anticipate when the “second rise” tends to happen for your child.
Keep It Positive
Food is a big part of social life for kids and teens. Pizza parties, chips with friends, pasta dinners after sports- they shouldn’t feel like these foods are off-limits. Instead, think of it as detective work: “How does this meal affect me, and what can I do next time to stay in range?” Over time, your child will get better at predicting and adjusting.
Final Thoughts
Pizza, pasta and potatoes aren’t sneaky villians- they just play by different digestion rules. Understanding the science of carbs + fat + protein, and learning some smart strategies, can help you and your child stay ahead of those double spikes while still enjoying favourite foods.
