We asked people with type 2 what surprised them after meals. Their answers didn't agree.
People with type 2 diabetes reported very different reactions to similar foods, and research on healthy adults shows glucose responses to identical meals vary widely. A three-day test with your own breakfast shows how your body responds.
Last month we asked a large type 2 diabetes group on Facebook what had surprised them most when they checked their sugar after eating. Our question suggested breakfast as one example, so keep that in mind. The replies went in more directions than we expected.
One member can eat bacon, sausage and eggs with no rise at all, unless toast goes on the plate. Cereal drew the most comments. One person finds it manageable by sticking to the portion on the box, and another had dried fruit in theirs and hadn't thought about the sugar it added. In a different group, a member saw 7.4 go to 10.4 mmol/L (133 to 187 mg/dL) after a small bowl of cereal. One member who takes insulin said walks do nothing for their numbers, though walking is the tip most people hear first.
These are people's own readings from a small conversation, so they aren't a study. Researchers have seen the same kind of variation under controlled conditions.
Why your meal may not act like someone else's
In the PREDICT study, about 1,000 healthy adults in the UK ate identical meals, and their glucose responses still varied widely. What was in the meal explained more of the glucose difference than genes or gut bacteria, and each explained only a modest share (Berry et al., Nature Medicine, 2020). The volunteers didn't have diabetes, so it's a guide to how much people differ and can't tell you how your own sugar will respond.
A list of good and bad foods can only take you so far. Glycemic index tables describe an average person, and your own numbers tell you the rest.
A three-day test
Pick the breakfast you eat most often. On day one, eat it as usual and check your sugar before you eat and again two hours after you start. On day two, keep the meal the same but change one thing: add an egg or some nuts, swap juice for whole fruit, or eat the protein first. On day three, repeat day one or day two, whichever surprised you, because a single reading can mislead.
If you take medicine that can cause lows, check with your doctor before you change what you eat in the morning.
Where we come in
The Journey for Health app lines up each meal with the rise that followed, so you don't have to keep a notebook. If you'd like to go through your own numbers with someone, the first call with one of our experts or coaches is free.
If you look after benefits for a workforce and want to see how this works for a whole team, get in touch.
Talk to an expert or coach. The first call is free
Common questions
Why does the same meal affect people differently?
In the PREDICT study of healthy adults, glucose responses to identical meals varied widely. Meal content, genes and gut bacteria each explained part of the difference, and none explained most of it.
How can I test a meal on myself?
Check your sugar before a usual breakfast and two hours after you start. The next day change one thing, then repeat the one that surprised you on the third day.
Should I change my breakfast if I take medicine that can cause lows?
Check with your doctor first, because eating less or differently in the morning can change how that medicine affects you.
Sources
- Berry SE et al. Human postprandial responses to food and potential for precision nutrition. Nature Medicine 2020
- Zeevi D et al. Personalized nutrition by prediction of glycemic responses. Cell 2015;163(5):1079-1094
- Shukla AP et al. Food order has a significant impact on postprandial glucose and insulin levels. Diabetes Care 2015;38(7):e98-e99
Last updated: . Educational information, not medical advice. Talk to your doctor before changing your treatment.