The short answer: Yes, but only occasionally.
The long answer: Containing the highest amount of protein among all the bean varieties, soybeans come from a legume native to East Asia. This type of bean is commonly cultivated and used as a whole or processed to make soy milk and tofu. Their hairy pods resemble green beans, but are flatter and come in a duller shade of green. When mature, the pods turn tan while the beans are light brown, tan, or beige in colour. Edamame is an immature soybean, which is steamed as a whole then eaten without the pod.
Cooked soybeans can be given to your cat as long as she is not allergic or intolerant to the bean, and she does not have any existing conditions that might affect it. However, since soybeans do not contain the essential nutrients cats need to function properly, it is best to give them sparingly.
Raw soybeans, on the other hand, are not recommended for cats since they may have bacteria and toxins resting on their outer coat. These may cause various complications such as lethargy, gas, vomiting, nausea, diarrhea, and abdominal pain.
How to feed soybeans to your cat: Soak the fresh or dried beans in water overnight. Cook them in boiling water for three to four hours or until tender. Do not add unnecessary flavourings such as salt, onion, garlic, and other herbs and spices. These common kitchen ingredients are highly toxic for your cat.
When feeding soybeans to your cat for the very first time, exercise caution and only serve her a small portion. Monitor her for any changes in her mood, eating habits, and litter box visits. If she does not manifest any adverse effects, you can feed her a bit more the next time around.
In summary: Rich in protein, fiber, phytic acid, and isoflavone, soybeans can be eaten by your cat from time to time, but only in small amounts. Overfeeding her with soybeans can cause gastrointestinal issues such as indigestion, gas, and diarrhea. This is because your cat’s stomach does not have the capacity to digest soybeans properly.