Grain Free Text In Kibble

‘Grain-free’ has become somewhat of a buzzword in dog food. When you take a stroll down any pet food aisle, these words are in massive bold letters, emblazoned across the front of a good portion of the options.

What Does Grain-Free Mean And Should You Care?  

To understand what ‘grain-free’ is, we must first understand what grains are.

Grains are the edible parts of cereals, and the term includes several types: wheat, barley, maize (corn for us Brits), rice, oats, and more. However, not all grains are created equal. Some, like wheat and maize, are more troublesome for our dogs than others. We should also take note of if the grains used are whole or refined: whole grains can offer beneficial nutrients to our dogs, whilst refined grains (like white rice) only really offer starch.

Bags Of Grains

Grains are typically included in pet food as a source of carbohydrate.

Carbohydrates offer an energy source that is easy to access, as well as a source of fibre. Both of these features are useful for your dog: fibre helps to keep the gut healthy, and carbohydrate (whilst not essential) is a good source of energy1. The trouble with this, however, is that it’s fairly common for our dogs to eat too much carbohydrate – which is problematic.

 Whilst many people claim that dogs have not evolved to digest grains, there have been plenty of studies that prove dogs can actually digest grains just fine1,2. In fact, they’ve evolved to have this written into their genes3. This makes the carbohydrate content of foods incredibly important, as our dogs are capable of digesting up to 99% of it2.

Why Are Grain-Free Diets So Popular?

The first thing to note about grain-inclusive diets is that they are more prone to mould growth4, as well as growth of mycotoxins5, which are both dangerous for your dog to eat. Switching to grain-free reduces this risk, which makes grain-free diets automatically safer for your dog.

Mould On Bread

On top of this, though, grain-free diets have a lower carbohydrate content than their grainy counterparts4. Whilst carbohydrates are a handy energy source, too much of them leads to too much energy and a massive spike in blood sugar. These will give you a hyperactive dog in the short-term but, in the long-term, you may be faced with an obese dog with diabetes1. That means your dog could suffer, and you may be faced with some hefty vet bills. If you want to know how much carbohydrate your dog should be eating, take a look at this article.

Despite this, some grain-free diets also have high amounts of carbohydrates in them, as the substitutes they use for grains are often still rich in starch. The main culprit for this is white potato, as it releases its energy quickly – so it’s not much better than having a grain-based food.

Potatoes And Beans

Good carbohydrate alternatives may be found in legumes, such as peas and lentils, although this can also be a warning sign. Foods can often rely on legumes to boost their protein content: however, the protein provided by peas and lentils is less digestible (and therefore worse quality) than meat-based protein6. When food manufacturers add significant amounts of legumes, it usually means that there isn’t enough good-quality protein already in the diet. They then add the legumes as a means to save costs and make the food cheaper, whilst still appearing healthy to the untrained eye.

A better alternative for a grain substitute is sweet potato. This is because it has a low to medium glycemic index7, which means it releases its energy over a longer time period than its counterparts. This means a more emotionally and behaviourally stable dog, as well as reducing the chances of obesity and diabetes later in life.

Finally, grain-free diets also tend to have more digestible protein and fat in them8. This means your dog can get all of the nutrients they need from a smaller portion of food, saving you money and helping reduce the chances of your dog experiencing bloat.

Sweet Potato

So, what is the best carbohydrate source for your dog food? Sweet potato! Sweet potato will give your dog a good source of carbohydrate for energy, delivered in a slow-release format, whilst also delivering several important vitamins and antioxidants. It’s also less likely to get mouldy than grain-based diets, and will also help your dog to digest all of the other ingredients in their meals.

The great news is that loads of good quality foods exist that use sweet potato as the main carbohydrate. These include: 

As always, if you have questions about what to feed your dog, get in touch for your FREE 10 minute nutrition consult today. Simply email, and we’ll get you booked in!



1Rankovic, A., Adolfe, J.L., and Verbrugghe, A. (2019) Role of carbohydrate in the health of dogs. Journal of the American Veterinary Medical Association. 255(5): 546-554. 

2LaFlamme, D., Izquierdo, O., Eirmann, L., and Binder, S. (2014) Myths and misperceptions about ingredients used in commercial pet foods. Veterinary Clinics of North America: Small Animal Practice. 44(4): 689-698

3Axelsson, E., Ratnakumar, A., Arendt, M.L., Maqbool, K., Webster, M.T., Perloski, M., Liberg, O., Arnemo, J.M., Hedhammar, A., and Lindblad-Toh, K. (2013) The genomic signature of dog domestication reveals adaptation to a starch-rich diet. Nature. 495: 360-364.

4Kazimierska, K., Biel, W., Witkowicz, R., Karakulska, J., and Stachurska, X. (2021) Evaluation of nutritional value and microbiological safety in commercial dog food. Veterinary Research Communications. 45: 111-128.

5Tegzes, J.H., Oakley, B.B., and Brennan, G. (2019) Comparison of mycotoxin concentrations in grain versus grain-free dry and wet commercial dog foods. Toxicology Communications. 3(1): 61-66.

6Donadelli, R.A., Jones, C.K., and Beyer, R.S. (2019) The amino acid composition and protein quality of various egg, poultry meal by-products, and vegetable proteins used in the production of dog and cat diets. Poultry Science. 98(3): 1371-1378.

7Allen, J.C., Corbitt, A.D., Maloney, K.P., Butt, M.S., and Truong, V.D. (2012) Glycemic index of sweet potato as affected by cooking methods. The Open Nutrition Journal. 6: 1-11.

8Chiofalo, B., De Vita, G., Presti, V.L., Cucinotta, S., Gaglio, G., Leone, F., and Di Rosa, R. (2019) Grain-free diets for utility dogs during training work: Evaluation of the nutrient digestibility and faecal characteristics. Animal Nutrition. 5: 297-306. 


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