Is a Grain-Free Diet Best for Cats? Q&A with Dr. Leilani Alvarez, DVM

Grain-free diets have been around for years, but they have become increasingly popular in the past decade.

While there’s an obvious benefit to feeding high-protein diets, there’s also a lot of confusion regarding the benefits of grain-free foods, why grain-free and low-carb are not necessarily the same thing, and how to decide whether you should be shunning grains and switching your cat’s diet.

We talked to Dr. Leilani Alvarez, DVM, DACVSMR, Director of Integrative and Rehabilitative Medicine at the Animal Medical Center in NYC, to find out more about the benefits of a grain-free diet for cats and when it makes sense to give it a try.

THK: Feeding a grain-free diet has been a trend for years. Why is it particularly important to feed your cat grain-free food?

LEILANI ALVAREZ: Cats are obligate carnivores; therefore, their natural diets are generally very low in grains. An ideal diet for a cat should be high in meat-based protein, moderate in fat and low to minimal in carbohydrates—low-carb is more important than grain-free.

It’s important to note though, that grain-free does not necessary mean low-carb. There are many other sources of carbohydrates that are grain-free, such as potatoes and other starches. Tapioca, for example, is grain-free but a very unnatural source of carbs for a cat. In fact, a recent study published in the Journal of Feline Medicine and Surgery showed that some grain-free cat diets are higher in carbs than grain diets.

THK: Do cats have any biological need for grains?

LA: Not in a strict sense; however, cats in the wild tend to eat their whole prey. This includes muscle, bone and stomach contents, which usually contain grains, fiber, and other nutrients.

THK: If someone is feeding grain-free cat food, what are some signs that a cat might be having allergies or other issues?

LA: Food allergies are generally infrequent in cats. Common signs of food intolerance include an upset stomach (vomiting or diarrhea) and weight loss.

I would say that grain allergies are pretty uncommon in cats. That’s not to say that all cats tolerate grain-free diets well, but for sure, high-carb diets are not healthy for cats. Reviewing food labels (which is not as easy as one might think) is important. Look for diets where the first listed ingredients are meat-based proteins and carb sources should be low on the list.

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THK: Can issues with grains be confused with issues caused by other food ingredients?

LA: Most definitely! Food allergies generally are more likely to develop against a protein source (beef, dairy, chicken) rather than to a carbohydrate source. Again, remember also that food allergies are pretty rare in cats. I will say that some pretty exotic ingredients can show up in grain-free diets that could be problematic since they are so unusual and never something a cat would normally eat—like celery, watercress, blackberry, avocado, artichoke, apricot.

THK: Cats are infamously finicky eaters. Can feeding grain-free cat food lead to better or more consistent eating?

LA: In general yes, because grain-free diets tend to be higher in protein content and cats love their meat-based protein!

THK: Are there any medical reasons why a cat would do better with whole grains in the diet?

LA: Definitely. Cats that are underweight or are highly active and need extra calories can benefit from grains in their diet. There can also be other reasons such as an inability to gain weight, pregnant or lactating cats (that have higher energy requirements).

THK: If a particular cat needs a lower protein diet, but the cat is intolerant or allergic to grains, what is a good carbohydrate option?

LA: My favorite is sweet potatoes. Sweet potatoes are naturally rich in Vit A and C and have a low-glycemic index, which is better for cats that might be prone to diabetes. From a Traditional Chinese Medicine perspective, sweet potatoes are also great food for Qi tonification and help normalize digestion. Other good options include white potatoes, peas, and quinoa.

The Honest Kitchen offers grain-free foods made up of 100% human-grade, high-quality protein such as cage-free turkey, wild-caught white fish, and organic free-range chicken. If you have questions not covered above, please feel free to reach out to us at

Meet the Author: Diana Bocco

Diana Bocco is a full-time writer and avid adventurer. She's gone hiking in Siberia, snorkeling in Thailand, and canoeing in the Mekong River. She also loves caves and has been known to get lost in one or five around the world. Diana's work has been published in the Discovery Channel website, Yahoo!, Popular Mechanics, and more. You can read more of her work on her website at

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