The most important decision we make for our pets each day is what to feed them, and the first step in making a wise choice is reading the label. But there’s a lot that labels don’t reveal. Unlike human food labels that gives precise amounts of protein, fat and carbohydrates per serving, pet food labels only provide protein and fat minimums (not actual amounts) expressed as a percentage, and fiber and moisture maximums (again, not actual amounts). Here’s information not on the label that you really want to know:
How Many Carbohydrates?
The level of carbohydrates in a food is a vital piece of information. For dogs and cats, too many carbs is public enemy #1, elevating blood sugar and leading to obesity, diabetes and other chronic health conditions. High quality canned and raw foods are naturally low in carbs, but in dry foods they can range from 60% to less than 20%. While some of that comes from healthy sources, like fiber from fruit and vegetables, too many refined carbohydrates from high glycemic starches like potatoes or rice is a bad thing. We prefer diets with less than 20% total carbs for cats and less than 35% for dogs.
Here’s a simple formula to estimate carb content of dry foods using information given in the guaranteed analysis:
ADD: Protein + Fat + Moisture + Ash (use 8% if not listed)
SUBTRACT total from 100 for estimated % of Carbohydrates* “as fed”.
*Fiber is not added because it is a part of total carbohydrates
Example: 38% protein + 18% fat + 10% moisture + 8% ash = 74%.
Subtract: 100 – 74 = 26% carbohydrate
If your chosen dry food has more carbs than you would like, try serving less of it and making up the difference with some protein-rich raw or freeze-dried added to the bowl, raising protein and reducing overall carbs.
Note: When calculating carb content of canned or raw food, if you convert all values to a dry matter basis by dividing each one by the percentage that is not moisture (i.e .25 if moisture equals 75%), before using the formula, it will give you more meaningful results.
Bioavailable protein vs. crude protein
The percentage of crude protein on a label can be misleading because there are so many different grades of ingredients and the amino acids your pet can utilize depends on that. Whole egg is the perfect protein, with 100% bioavailability. Meat, poultry and fish are typically 75 – 85% bioavailable, but if there’s a lot of bone, gristle and connective tissue, the bioavailability will be much lower. Plant-based proteins, like chickpeas, lentils or peas are incomplete and have a fairly low protein levels. Determining protein quality from the label is a daunting task, and there is no formula. AAFCO rules require very little protein to begin with (18% for adults and 22% for growth) with no standards at all for digestibility or biological value.
Scrutinizing the ingredient label for a higher total of bioavailable ingredients can really pay off in your dog or cat’s well-being. Take a close look at the actual proteins listed, not just the protein percentage on the label. When it comes to interpreting pet food labels, the results you see in your pet over the long run and the reputation of the pet food manufacturer are your best guides. And you can always ask a pet care specialist to suggest some options for your particular pet’s needs.