Blackberries are a delicious, low glycemic index fruit that can be enjoyed as part of a ketogenic diet. With only 5 grams of net carbs per cup, blackberries contain fiber and antioxidants without significantly impacting blood sugar or insulin levels. However, some people worry that the natural sugars in blackberries could knock them out of ketosis. So what’s the real scoop on blackberries and ketosis?
What is Ketosis?
Ketosis is a natural metabolic state in which the body switches from primarily burning glucose derived from carbohydrates to primarily burning fats for energy. This produces ketones, which become the main fuel source for the body and brain. Ketosis occurs when carb intake is restricted to around 50 grams of net carbs or less per day. This reduction in carbs forces the body to burn through glycogen stores. Once glycogen is depleted, the body transitions into ketosis.
Being in ketosis provides several benefits including:
Weight Loss
Burning fat instead of glucose encourages the body to tap into stored body fat for energy. This leads to significant weight loss and body fat reduction.
Appetite Suppression
Ketosis helps regulate hunger hormones, like ghrelin, leading to decreased appetite. You may feel fuller for longer periods of time when following a ketogenic diet.
Stable Energy Levels
Unlike glycogen from carbs which provides short bursts of energy, ketones provide a steady supply of fuel for hours. This leads to stable energy and focus throughout the day without crashes.
Reduced Inflammation
Ketosis has been shown to have anti-inflammatory effects in the body, which may improve various health conditions worsened by inflammation.
Improved Blood Sugar Control
The ketogenic diet can lower blood sugar levels and improve insulin sensitivity in those with type 2 diabetes or prediabetes.
Staying in ketosis requires strict adherence to a low carb, high fat keto diet. Even small amounts of excess carbs can knock you out of ketosis, depending on the individual. So do blackberries contain enough carbs to disrupt ketosis? Let’s find out.
Carb Content of Blackberries
Here is the carb breakdown for 1 cup (144g) of raw blackberries according to the USDA Food Composition Database:
| Total Carbohydrates: | 14.49g |
| Dietary Fiber: | 7.6g |
| Sugar: | 7.03g |
| Net Carbs: | 6.89g |
As you can see, a typical serving of blackberries contains 14.49 grams of total carbs. But 7.6 grams comes from fiber, which does not raise blood sugar or impact ketosis. Fiber passes through the body undigested, so we can subtract it from the total carbs to calculate the net carbs. For blackberries, the net carb count comes out to just 6.89 grams per cup.
This carb content is considered low for most fruits. Comparatively, other fruits contain significantly more net carbs per serving:
| Bananas: | 24g net carbs per cup |
| Grapes: | 16g net carbs per cup |
| Apples: | 15g net carbs per cup |
| Mangoes: | 13g net carbs per cup |
With 3-4 times fewer net carbs than these other popular fruits, blackberries clock in as a more keto-friendly choice.
Effect of Blackberries on Ketosis
To understand how blackberries impact ketosis, we need to look at their effect on blood sugar and insulin. The two main factors that influence ketosis are carb intake and personal carb tolerance.
On the carb intake side, blackberries contain a low enough amount of net carbs that they likely won’t exceed most people’s daily carb limits on keto. The standard ketogenic diet recommends consuming 20-50 grams of net carbs per day. This allows room for 1-3 servings of blackberries while staying within range.
However, low carb intake alone doesn’t guarantee you’ll remain in ketosis. Individual carb tolerance varies greatly from person to person. Some keto dieters may be able to stay in ketosis with as many as 50-100 grams of carbs per day, while others may get kicked out of ketosis with just 30-40 grams.
Looking at the glycemic index (GI) and glycemic load (GL) scores for blackberries gives us more insight into their potential effect.
GI measures how quickly a food raises blood sugar. GL takes into account how much an average serving will raise blood sugar based on GI and serving size.
Blackberries have a GI of 25 and a GL of 2, making them a low glycemic, low impact fruit. This means they shouldn’t lead to significant spikes in blood sugar or insulin when eaten in normal amounts. Maintaining steady, low blood sugar and insulin levels is key for staying in ketosis.
Additionally, blackberries have a high antioxidant content which may help mitigate blood sugar response. The anthocyanins that give blackberries their deep purple hue are powerful antioxidants that lower oxidative stress and inflammation, leading to improved insulin sensitivity.
Based on their macronutrient profile and glycemic response, regularly incorporating blackberries into a keto diet is unlikely to disrupt ketosis for most people. However, individuals vary in their responses to different foods. Some may be highly sensitive to the natural sugars in blackberries while others remain unaffected.
Tips for Incorporating Blackberries into a Keto Diet
Blackberries can be safely enjoyed as part of a well-formulated ketogenic diet for most people. Here are some tips for incorporating them:
Stick to Portion Control
Aim to keep blackberry intake to around 1 cup (144g) per day to stay within typical keto carb ranges. Measure out servings rather than guessing.
Avoid Going Overboard
Even though blackberries are low glycemic, overdoing intake could make it easier to accidentally knock yourself out of ketosis.
Pair with Protein, Fat or Fiber
Eating blackberries along with protein, fat or high fiber foods helps slow digestion and blood sugar response.
Test Ketones
Use ketone urine test strips or a breath meter to monitor your individual response. Check ketones 1-2 hours after eating blackberries to see if they impact you.
Watch Total Carbs
Don’t let blackberries become an excuse to go over your total daily carb limit. Keep total carbs under 50g per day.
Choose Very Low Carb Days
On days when you want to indulge in blackberries, cut back carbs to under 30g for the day. Just monitor ketones afterward.
Time with Physical Activity
Eating blackberries around exercise helps minimize any effects on ketosis.
The Bottom Line
Blackberries contain minimal net carbs and have little impact on blood sugar. When enjoyed in moderation as part of an overall low carb diet, blackberries should not disrupt ketosis for most people. However, individuals vary in sensitivity to varying carb intakes. Monitor your personal response by testing ketones and making sure not to exceed your daily carb limits. With smart incorporation, blackberries can be a fresh, sweet addition to a sustained keto lifestyle.
