How many calories in a very large portobello mushroom?

Portobello mushrooms are a popular ingredient used in many dishes. They have a meaty, rich flavor that makes them a great vegetarian substitute for burgers and other recipes. But many people wonder just how many calories are in these large, hearty mushrooms.

What is a Portobello Mushroom?

Portobello mushrooms are actually just mature cremini mushrooms. Cremini mushrooms are tan in color and are sometimes called baby bellas. When left to fully grow, cremini mushrooms develop into large, dark brown mushrooms with wide caps and meaty texture. These larger mature cremini mushrooms are given the name portobello mushrooms.

Some key facts about portobello mushrooms:

– They have a rich, earthy, umami flavor. The flavor is more intense than white button mushrooms.

– The texture is meaty and dense. When cooked, the mushroom has a steak-like texture.

– Portobello caps can measure 4-6 inches across. The stems are thick and plump.

– They have high nutritional value with antioxidants, B vitamins, potassium and fiber.

– Portobellos can be used similarly to meat. They are great for vegetarian/vegan burgers, fajitas, skewers and more.

– When raw, portobellos should feel heavy and dry with tightly closed caps. Avoid mushrooms with cracked, wet or shriveled caps.

Nutrition Facts for Portobello Mushrooms

One large, 5-6 inch portobello mushroom contains approximately:

– Calories: 42
– Fat: 0.3 g
– Carbs: 9 g
– Fiber: 3 g
– Protein: 3 g

Portobello mushrooms are very low in calories and fat. Most of the calories come from carbohydrates. They are a good source of fiber, providing about 10% of the recommended daily value.

The protein content is also fairly high for a vegetable – about 3 grams per mushroom. This contributes to their hearty, meaty texture.

Portobellos are low in most vitamins and minerals. But they do contain a significant amount of potassium, copper and B vitamins like riboflavin, niacin and pantothenic acid.

They are also high in antioxidants like polyphenols and ergothioneine. Antioxidants help reduce inflammation and protect cells from damage.

So in terms of nutrition, portobello mushrooms provide a good amount of fiber, potassium and antioxidants with very minimal calories and fat.

Calories in Large Portobello Mushrooms

Now that we know the basic nutrition facts, how many calories are actually in a very large portobello mushroom?

Most sources estimate approximately 42 calories per average-sized large portobello mushroom that is around 4-6 inches wide.

But mushrooms can vary in size, so the number of calories can range based on the individual mushroom’s dimensions.

Here are some calorie estimates for different sizes of whole portobello mushroom caps:

– Small, 3 inch cap: Around 25 calories
– Medium, 4 inch cap: Around 35 calories
– Large, 5 inch cap: Around 45 calories
– Extra-large, 6+ inch cap: Around 60+ calories

The smaller the cap, usually the fewer calories it will contain. The calorie count scales up as the size of the mushroom cap increases.

More specific estimates for very large portobello mushrooms:

– 7 inch wide cap: Around 70 calories
– 8 inch wide cap: Around 85 calories
– 9 inch wide cap: Around 100 calories
– 10 inch wide cap: Around 120 calories

As you can see, once you get into the range of extremely large mushroom caps that are 8 inches or wider, the calorie count can start approaching 100-120 calories for a single mushroom.

The stem or stalk alone contains very minimal calories – usually 5 calories or less per inch of stem.

How Cooking Affects Calories

When you cook portobello mushrooms, it slightly changes their calorie and nutrition profile.

Cooking mushrooms causes them to lose some water content, so the calories and nutrients become more concentrated.

For example, 1 cup of raw sliced portobellos contains around 28 calories.

1 cup of cooked, sautéed portobello slices contains about 39 calories.

So cooking increases the calorie density slightly, but the total calories remain very low.

Other ways cooking impacts portobellos:

– Protein increases – cooking breaks down cell walls, making protein more available.
– Fiber decreases – some fiber is lost in cooking water.
– Vitamin C decreases – vitamin C is degraded by heat and oxygen.
– B vitamins increase – heat makes them more bioavailable.
– Potassium decreases – leaches out into cooking liquid.

So cooking does cause some beneficial and negative changes. But the overall nutrient profile remains very similar. Portobellos maintain their status as a healthy, low-calorie food whether they are raw or cooked.

Calories in Common Portobello Recipes

Portobello mushrooms are extremely versatile. They can be used as a meat substitute in many vegetarian recipes.

Here are the approximate calories when portobellos are used in some common recipes:

Portobello Burger:

– 1 large grilled portobello cap: 50 calories
– 1 whole wheat bun: 150 calories
– 2 tomato slices: 10 calories
– 1⁄2 cup sautéed onions: 30 calories
– 1 lettuce leaf: 1 calorie
– 1 tbsp light mayo: 25 calories

Total Calories: Around 265 calories

Portobello Fajitas:

– 1 large grilled portobello: 50 calories
– 1 bell pepper: 25 calories
– 1⁄2 onion: 40 calories
– 2 tbsp salsa: 10 calories
– 1 tbsp guacamole: 25 calories
– 1 tortilla: 150 calories

Total Calories: Around 300 calories

Portobello Pizza:

– 2 large portobello caps: 100 calories
– 1⁄4 cup pizza sauce: 60 calories
– 2 tbsp Parmesan: 55 calories
– 1⁄4 cup mozzarella: 80 calories
– Toppings like vegetables: 50 calories

Total Calories: Around 350 calories

As you can see, even when incorporated into full recipes, portobello mushrooms add very minimal calories – typically only around 50-100 calories per serving.

This makes them an excellent low-calorie substitution for meat in main dishes and sandwiches.

Tips for Preparing Low-Calorie Portobellos

Here are some tips for keeping portobello mushrooms low in calories:

– Remove stems before cooking – the caps are lower calorie than the stems.
– Roast, grill or sauté in cooking spray or small amount of olive oil.
– Avoid frying or breading them. This increases the calorie count significantly.
– Use healthy toppings like tomatoes, onions, basil – avoid high-calorie cheeses.
– Opt for light dressings and condiments like mustard or hot sauce.
– Pair with non-starchy veggies like spinach, broccoli and bell peppers.
– Use whole grain buns and baked tortillas instead of white, refined options.
– Limit high-calorie additions like avocado, ranch or heavy sauces.

Enjoying portobellos prepared simply using light cooking methods keeps their calories minimal. With some reasonable portion control, they can be part of an overall healthy, low-calorie diet.

Portobello Mushroom Calories in Recipes

Here is a table summarizing the approximate calories in portobello mushrooms when used in various recipes:

Dish Portobello Calories (per serving)
Portobello burger 50 calories
Portobello fajitas (2 fajitas) 100 calories
Portobello pizza (2 slices) 50 calories
Portobello caps stuffed with rice 75 calories
Portobello stroganoff with noodles 60 calories
Grilled portobello kebabs (2 skewers) 80 calories

As shown in the table, portobello mushroom calories remain low even when incorporated into full recipes. A typical serving of a portobello dish will provide around 50-100 calories from the mushrooms themselves.

Nutrition Benefits Beyond Calories

When considering portobello mushrooms, it’s important to look beyond just calories. They provide a powerhouse of additional nutrition benefits:

Fiber – A 5-6 inch portobello contains 3 grams of dietary fiber. This aids digestion and gut health.

Potassium – Portobellos contain even more potassium than bananas, helping muscles and nerves function.

Riboflavin – This B vitamin helps convert food to energy and is important for red blood cell production.

Niacin – This B vitamin promotes healthy digestion and converts nutrients into usable energy.

Antioxidants – Compounds like polyphenols and ergothioneine exhibit antioxidant activity to reduce cell damage.

Selenium – This mineral has antioxidant properties and is important for thyroid and immune function.

Copper – Copper assists with iron metabolism and nerve transmission. Portobellos provide about 15% of the RDI.

So in addition to being low-calorie, portobello mushrooms deliver a significant amount of nutrients, antioxidants and health-promoting compounds. This makes them a very nutritious, filling and healthy addition to your diet.

Are Portobellos Weight Loss Friendly?

Due to their stellar nutrition profile, portobello mushrooms can be a very diet and weight loss friendly food:

– They are low in calories, providing only 35-50 calories per average-sized mushroom cap. This makes it easy to control calorie intake.

– They provide volume and take up space on your plate, increasing satisfaction from smaller servings.

– The fiber content (3 grams per mushroom) helps promote fullness and satiety after a meal.

– Portobellos have a hearty, meaty texture that can replace higher-calorie meats in many recipes.

– The high water content hydrates the body and may help reduce overeating.

– They have a neutral flavor that pairs well with healthy herbs, spices and vegetables.

– B vitamins like niacin help convert food into usable energy to power your workouts.

– Potassium regulates fluid balance required during exercise and helps muscles contract.

So thanks to the ability to bulk up dishes for few calories plus their stellar nutrient content, portobellos are an excellent choice for those looking to lose or manage their weight.


Portobello mushrooms are low in calories but pack a nutritional punch.

A large, 5-6 inch wide portobello cap contains around 40-50 calories. Very large caps over 6 inches wide may have up to 60-120 calories.

When added to recipes, a typical serving of portobello dishes will provide around 50-100 calories from the mushrooms themselves.

In addition to being low in calories, portobellos boast an array of beneficial nutrients including antioxidants, B vitamins, selenium and copper.

Their meaty texture, versatility and nutrition profile make portobellos an excellent substitute for higher calorie meats. Enjoying them as part of an overall healthy diet can support potential weight loss.

So the next time you need a hearty, plant-based ingredient, look no further than nutrient-packed portobello mushrooms. Their deep, savory flavor and low calorie count makes them perfect for any weight conscious foodie.

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