Your standard tomatoes have four grams of carbs and two grams of sugar per half cup serving, according to the United States Department of Agriculture (USDA). However, the counts vary a little depending on the type of tomato you go for.Click to see full answer. Accordingly, how many carbs do tomatoes have in them?Tomatoes contain about 3 grams of net carbs per 100 grams (about 5 grams per cup). But if you’re eating a strict keto low-carb diet (below 20 grams per day) it’s worth keeping in mind that the carbs do add up, and you can only eat a moderate amount of tomatoes to stay under that limit.Likewise, how much sugar is in a can of tomatoes? Nutrition Facts Calories 20 (84 kJ) Sodium 130 mg 5% Total Carbohydrate 3 g 1% Dietary Fiber 1 g 4% Sugars 2 g People also ask, can you eat tomatoes on a keto diet? While tomatoes are technically a fruit, you can have them on a keto diet, but again be careful as their carbs are a bit higher and, combined with other foods, may take you up over 20 grams net carbs a day if you consume too much.Do tomatoes raise blood sugar levels?Carbohydrates, especially the refined kinds, get metabolised quickly and causes blood sugar spike. Tomatoes are non-starchy and also have a low glycaemic index. About 140 grams of tomato has a GI of less than 15, which makes it a low GI food and an excellent food for diabetics.