Adding mushrooms to your diet can help with weight loss. Mushrooms are of course low in calories and quite filling. On top of that they are rich in fiber and protein, which can help you feel fuller for longer and reduce unnecessary snacking. Then several well known mushrooms also have compounds which can in theory help with fat metabolism, although the science there isn’t quite as good.
The Role of Mushrooms in Weight Management
Mushrooms are packed with dietary fiber and protein as we mentioned. Both of these create a feeling of fullness. This satiety effect can lead to reduced calorie intake, aiding in weight loss. 
Low Energy Density
Foods with low energy density of glycemic index like mushrooms have been shown to aid in weight loss. These foods provide fewer calories compared to their weight allowing you to eat large and thus satisfying portions while keeping your calorie intake in check. 
Mushrooms have a meaty texture that makes them a great substitute for higher fat meats, sure it’s not a perfect solution, but it is none the less effective. 
Mushrooms and Metabolic Health
Blood Sugar Regulation
Mushrooms are low in carbs making them a good food choice for people with diabetes. Some research also suggests that certain types of mushrooms may have compounds with properties that help regulate blood sugar levels. 
Certain types of mushrooms like shiitake and oyster mushrooms contain compounds that have been shown to lower LDL or "bad" cholesterol.
Which Mushrooms Are Best For Weight Loss
Chaga: A Potent Antioxidant and Adaptogen
Chaga mushrooms are mostly known for their antioxidants. These mushrooms are also adaptogenic meaning they can help to lower cortisol levels which can of course help with dieting by reducing stress eating. Typically chaga mushrooms are typically consumed in tincture or powdered form rather than as a food they can be added to drinks and smoothies as part of a blend. 
Chaga Calories: 180 calories per 100grams of powder
Lion's Mane: Enhancing Memory and Cognitive Function
Lion's mane mushrooms are mostly used to improve memory and cognitive function.
While lion's mane is commonly found in supplement form it is also becoming more available in stores since it’s become more popular in restaurants. The unique appearance of lion's mane mushrooms, resembling the fluffy mane of a lion which is the main reason for its recent appeal.
Lions Mane Calories: 43 Calories per 100g
Turkey Tail: Promoting Weight Loss Through Blood Sugar Control
Turkey tail mushrooms contain a high volume of beta glucans, a type of dietary fiber that have been shown to help with weight loss. These compounds regulate the body's metabolism slowing down the absorption of carbohydrates and improving blood sugar control. Turkey tail mushrooms are usually consumed in powdered form. And regularly feature in the best mushroom supplements.
Turkey Tail Calories: 200 Calories per 100g
Reishi: Boosting Energy Levels and Reducing Fatigue
Reishi mushrooms are high in protein and high protein foods help you feel fuller for longer and reduce unnecessary snacking. There is also evidence to suggest that Reishi mushrooms have anti-fatigue properties giving you an extra boost of energy for workouts. Helping further weight loss goals.
Reishi Calories: 250 Calories per 100mg
Shiitake: Anti-Inflammatory Properties and Flavorful Additions
Shiitake mushrooms are known for their excellent anti-inflammatory properties and are commonly used in South East Asian stir-fries and soups.
The main benefit of shiitake is that they’re particularly low in calories even amongst mushrooms.
On top of that shiitake mushrooms contain compounds that help prevent lipid deposition in the body making them beneficial for weight loss efforts.
Shiitake Calories: 35 Calories per 100g
Maitake: Low in Carbohydrates and Beneficial for Gut Health
Similarly to shiitake, maitake aren’t overly difficult to find, moreso than the former, but still doable. And they’re also one of the lower calorie options. Maitake mushrooms are more easily found dried and rehydrated, but it’s a nice change from shiitake. 
Maitake Calories: 35 Calories per 100g
Portobello: Convenient and Versatile Mushroom
Unlike some of the more exotic mushrooms portobello mushrooms are widely available in most grocery stores. This convenience makes them an easy addition to any diet. While portobello mushrooms may not have the same unique properties as other varieties they’re still low in calories and rich in nutrients and can be a valuable addition to a weight loss plan.
Portobello Calories: 25 Calories per 100g
Additional Benefits of Edible Mushrooms
Some of the other benefits of the best mushrooms for weight loss include:
Lion's Mane Mushroom: Compounds found in lion's mane mushrooms may stimulate the growth of brain cells and protect against age-related cognitive decline.
Reishi Mushroom: Bioactive compounds in reishi mushrooms may support the immune system and help the body fight against infections.
Turkey Tail Mushroom: Polysaccharides in turkey tail mushrooms may enhance the body's immune system.
Chaga Mushroom: Rich in antioxidants, chaga mushrooms help protect the body against oxidative stress and inflammation.
Shiitake Mushroom: Along with being a good source of fiber, shiitake mushrooms contain compounds that help prevent lipid deposition in the body. In theory this can aid in maintaining fat loss while supporting weight loss efforts.
So, Can Mushrooms Help With Weight Loss?
Sure they can be a great low calorie addition to a diet and there is some evidence to suggest that they can help with fat loss due to compounds found within certain varieties such as shiitake.
1 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5065707/
2 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5380573/
3 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3622286/
4 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6266766/
5 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10384337/
6 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7958531/