Yes, you can eat raspberries on a keto diet in moderation. A 62g half cup of raspberries has 3g net carbs.
Blackberries also have about 3g net carbs per half-cup. Strawberries have more net carbs — about 4.5g net carbs per half cup of sliced berries — and blueberries have a whopping 9g net carbs per half-cup.
Why can you eat raspberries on a keto diet? Because raspberries are low in the sugars, starches, and other carbohydrates that make the keto diet stop working.
To stay on the keto diet, you need to get most of your calories from fat, some from protein, and very few from carbohydrates — generally 5% or less of your daily calories, or about 20g carbohydrates. When your body gets energy from fat, not carbohydrates, you enter a state called ketosis. During ketosis, your body produces less insulin, the hormone which regulates blood sugar, than when you eat carbohydrates. For most people, going into ketosis helps them control their appetite and lose weight.
The major exception to the 5%-or-less rule for carbohydrates is fiber. Fiber is technically a carbohydrate, but your body can’t digest it. It passes through your gut without contributing any calories, and it doesn’t affect your insulin level.
When you want to eat raspberries — or any other fruit — on a keto diet, look at the total number of carbohydrates in a serving, then subtract the fiber. Raspberries have 7g carbohydrates per half cup, but 4g of that is fiber according to the USDA Food Composition Database.
If you calculate net carbs in raspberries, here’s what you get:
7g carbohydrate - 4g fiber = just 3g net carbs in raspberries.
Just remember: all berries are not the same! Different berries have very different amounts of net carbs. Here’s a rundown of the most popular berries.
Net carbs per half-cup:
Raspberries: 3g Net Carbs
Blackberries: 3g Net Carbs
Strawberries (sliced): 4.5g Net Carbs
Blueberries: 9g Net Carbs
And here are the net carbs for a few berries you won’t find in the salad bar.
Net carbs per half-cup:
Cranberries: 4g Net Carbs
Boysenberries: 4.5g Net Carbs
Gooseberries: 4.5g Net Carbs
Mulberries: 6g Net Carbs
Elderberries: 8g Net Carbs
Goji berries (dried): 29g Net Carbs
If you don’t eat any other carbs for the day, you could eat 3⅓ cups raspberries and stay on your keto diet. For the sake of variety, stay with a half cup (62g) serving of raspberries with your keto meal. You’ll get roughly 18% of the daily recommended amount of Vitamin C and 10-16% of your daily fiber — and you’ll stay keto.