According to the Association for Pet Obesity Prevention, at least half of this country’s dog and cat populations are overweight.

The reason is pretty much the same as for their owners: taking in more calories than the body can use.

And the consequences are the same, too: increased risk for serious health problems, decreased quality of life, and shorter life span.

The answer to the problem is, of course, proper diet and exercise. However, choosing the proper food for your dog isn’t as easy as it might seem. Pet food manufacturers can be pretty cagey, playing to our senses and not necessarily providing what our dogs need.

Truly nutritious food doesn’t come cheap, but it’s a commitment we make to the health and longevity of our pets. So, pull out your magnifying glasses and let’s take an educated look at the list of ingredients in the food you give your dogs.

Dogs are carnivores, so their digestive tracts are set up to assimilate meat and fat. We can all agree that a high-quality, digestible meat-based protein should be the first ingredient listed. As a point of reference, if you look for the first source of fat, you can assume that anything listed above that is considered to be a main ingredient.

The protein in a good pet food will be a specifically named meat or meat meal. For example, it will say chicken, beef, salmon, or any of those meals. Avoid any generic meat ingredients such as meat, meat by-products, or fish meal. Stay away from by-product meals even if the species is identified.

Your dog isn’t interested in any food that contains corn as a first ingredient, or in corn gluten or soy meal as a main ingredient.

Fats are important for skin and coat health, as well as brain development. Look for specifically named fats and oils and a high percentage of omega fatty acids. Avoid nonspecifics such as animal fat, as well as mineral oil.

Carbohydrates should come in the form of whole ground grains and may also include potatoes. Avoid fragments of these, flours and unspecified grain sources.

Fiber is a carb that is not digestible by our pets. Avoid in particular corn bran, hulls from peanuts, rice, soybeans and oats.

Fruits and vegetables might sound good to us and look nice on a list of ingredients, but your pet doesn’t really need them. Avoid apple or grape pomace and citrus pulp.

Other ingredients which are further down on the list might include flavorings, which aren’t needed in a good dog food. Stay away from any highly rendered flavoring (digests) and those of unspecified origin such as meat broth.

Preservatives which should be avoided are BHA, BHT, Ethoxyquin, and Metabisulphite. Sweeteners and dyes are unnecessary and don’t have a place in quality brands.

Supplements such as glucosamine should not be the reason you choose a dog food, as the amounts included aren’t enough to be helpful. Especially avoid K3, menadione (a synthetic version of vitamin K).

If you do the research, you should be able to find a good quality dog food that is within your budget.

Reliable websites that can help you with your selection, or rate the food you’re already using, are dogfoodproject.com and petfoodadvisor.com.

The Humane Society, humanesociety.org, keeps track of recalled foods and treats. They suggest caution in buying any treats made in China. Recent recalls include Hartz Chicken Chews, Hartz Oinkies Pig Skin Twists, and Milo’s Chicken Jerky and Chicken Griller Homestyle Dog Treats.