Jam Glycemic Index
Medium GI · The honest verdict
A moderate blood-sugar rise
Glycemic index
51–65
reported range
Glycemic load
5
Low GL
This food's glycemic index is 51–65, which is Medium GI.
Jam sits in a middle ground for blood sugar: it has a moderate GI and a low glycemic load per tablespoon, but the high sugar density means a larger serving can spike glucose. It is not a food to avoid entirely, but portion size matters significantly. This is general nutrition information, not medical advice — people with diabetes should confirm serving guidance with their care team.
GI numbers vary by source, ripeness, and how a food is prepared. This is general nutrition information — not medical advice. If you manage diabetes, confirm specifics with your care team.
Key facts
Jam GI is estimated in the 51–65 range — a moderate-GI spread with significant added sugar.
One tablespoon of strawberry jam provides about 10 g of sugar — roughly 2.5 teaspoons.
Glycemic load of 10 or below is classified as low — a 1-tablespoon serving of jam sits at the low end of this range.
What's actually inside
Per 100 g, with your typical serving noted as 1 tablespoon (20 g). The carb family is what moves blood sugar — fiber is the number that softens the spike.
Total carbs
13g
Net carbs
12.7g
total carbs minus fiber
Fiber
0.3g
slows the glucose rise
- Sugars
- 10g
- Protein
- 0.1g
- Calories
- 50kcal
Notable nutrients
- Vitamin C2 mg
- Potassium15 mg
- Iron0.1 mg
Is it a smart choice for blood sugar?
GI is only half the story — portion (glycemic load) and what you eat it with decide the real-world effect. Here's the honest read.
The verdict
Use sparingly — small portions can fit but sugar content adds up quickly
Jam sits in a middle ground for blood sugar: it has a moderate GI and a low glycemic load per tablespoon, but the high sugar density means a larger serving can spike glucose. It is not a food to avoid entirely, but portion size matters significantly. This is general nutrition information, not medical advice — people with diabetes should confirm serving guidance with their care team.
Portion guidance
A 1-tablespoon serving (about 20 g) contains roughly 13 g of total carbs and a glycemic load of around 5, which is within the low GL range. Sticking to one tablespoon per meal and pairing it with protein and fiber — such as on whole-grain toast with peanut butter — keeps the overall glycemic impact moderate. Larger portions, such as 2–3 tablespoons, will raise GL meaningfully.
This is general nutrition information, not personal medical advice. Blood sugar responses are individual — if you have diabetes or prediabetes, your care team can tell you how this fits your plan.
How to keep the spike small
The same food can land differently depending on how it's cooked and what it's eaten with. Use these levers to your advantage.
Added sugar content
Raises GIConventional jam contains significant added sugar (often 40–60% of total weight), which raises the GI and GL. Reduced-sugar or no-sugar-added versions have a lower glycemic impact.
Fruit base
Raises GIJams made from higher-GI fruits (e.g., watermelon, pineapple) will tend toward the upper end of the GI range, while those from lower-GI fruits (e.g., berries) may be slightly lower.
Cooking and processing
Little effectThe cooking process used to make jam breaks down fruit cell walls and concentrates sugars, but this effect is consistent across most commercial jams. The primary driver of GI variation is added sugar content rather than processing method.
Pectin content
Lowers the spikePectin, a soluble fiber naturally present in fruit and often added to jam, can modestly slow sugar absorption and lower the glycemic response compared to eating pure sugar.
Pairing tip
Spread jam on whole-grain or seeded bread rather than white bread to add fiber that slows glucose absorption. Pair with a protein source like peanut butter, almond butter, or Greek yogurt to further moderate the blood sugar response. Avoid eating jam alone or with other high-sugar foods in the same meal.
Why GI numbers vary
Jam GI data is limited and varies across sources because of differences in fruit base, added sugar content, and pectin levels. Some studies report values around 51 for reduced-sugar berry jams, while others for conventional strawberry or apricot jam approach 65. The variation reflects real differences in formulation. We report the honest range (51–65) and classify jam as medium because the midpoint and most typical commercial jams land in that zone.
Not medical advice. This page is general nutrition information about Jam. It isn't a diagnosis or a treatment plan. If you have diabetes, prediabetes, or another condition affecting blood sugar, confirm any dietary decisions with your doctor or care team.
❓Frequently Asked Questions
Jam GI ranges from approximately 51 to 65 depending on the fruit base and added sugar content, making it medium by the midpoint. Reduced-sugar or no-sugar-added versions tend toward the lower end; conventional jams with high sugar content push higher. Because sources genuinely vary, we report a range rather than a single value. In practical terms, treat jam as a moderate-GI spread that should be used in small amounts.
Jam can fit into a diabetes-friendly diet in very small portions. A 1-tablespoon serving has a glycemic load of about 5, which is within the low GL range. However, jam is high in added sugar and provides little fiber or protein, so it can spike blood sugar if portion size is not controlled. People with diabetes should discuss serving sizes with their care team — this is general nutrition information.
Fresh fruit is generally better for blood sugar than jam because it contains intact fiber and water that slow sugar absorption, and it has no added sugar. A serving of fresh berries (e.g., 1 cup strawberries) has a similar carb count to 1 tablespoon of jam but with more fiber, vitamins, and a lower glycemic impact. Jam is a more concentrated sugar source and should be used sparingly.
Jam is high in sugar and not ideal for low-carb diets. One tablespoon provides about 13 g of total carbs, most of which are sugar. On a moderate low-carb plan (50–100 g net carbs/day), a single tablespoon can fit, but it uses a significant portion of the daily budget. On strict keto (under 20–30 g/day), even one tablespoon is difficult to accommodate. Sugar-free or reduced-sugar jams are better options for low-carb diets.
Yes, sugar-free jam typically has a lower GI because it uses artificial sweeteners or sugar alcohols (e.g., stevia, erythritol) instead of sugar. These sweeteners have little to no effect on blood glucose. However, some sugar-free jams still contain small amounts of natural fruit sugars, so the GI is not zero. Always check the label for total carbs and sugar content.
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Reviewed by
Curex Editorial TeamReviewed for accuracy
Last reviewed July 2026