Hill’s Science Diet Nature’s Best (Dry)



Hill’s Science Diet Nature’s Best dog food receives the Advisor’s mid-tier rating of three stars.

The Hill’s Science Diet Nature’s Best product line includes six dry dog foods… four designed to meet AAFCO nutrient profiles for adult maintenance and two for growth and reproduction.

  • Hill’s Science Diet Nature’s Best Adult Small Bites (Chicken)
  • Hill’s Science Diet Nature’s Best Adult Small Bites (Lamb)
  • Hill’s Science Diet Nature’s Best Puppy (Chicken)
  • Hill’s Science Diet Nature’s Best Adult (Chicken)
  • Hill’s Science Diet Nature’s Best Puppy (Lamb)
  • Hill’s Science Diet Nature’s Best Adult (Lamb)

Hill’s Science Diet Nature’s Best Lamb and Brown Rice Adult Small Bites dog food was selected to represent the others in the line for this review.

Hill's Science Diet Nature's Best Lamb and Brown Rice Adult Small Bites

Dry Dog Food

Estimated Dry Matter Nutrient Content

Protein = 25% | Fat = 16% | Carbs = 51%

Ingredients: Lamb, brewers rice, cracked pearled barley, soybean meal, brown rice, dried egg product, lamb meal, pork fat (preserved with mixed tocopherols and citric acid), soybean oil, powdered cellulose, natural flavor, whole grain oats, apples, cranberries, peas, carrots, broccoli, iodized salt, vitamins (l-ascorbyl-2-polyphosphate (source of vitamin C), vitamin E supplement, niacin, thiamine mononitrate, vitamin A supplement, calcium pantothenate, biotin, vitamin B12 supplement, pyridoxine hydrochloride, riboflavin, folic acid, vitamin D3 supplement), choline chloride, potassium chloride, vitamin E supplement, taurine, minerals (ferrous sulfate, zinc oxide, copper sulfate, manganous oxide, calcium iodate, sodium selenite), preserved with mixed tocopherols and citric acid, l-lysine, beta-carotene, rosemary extract

Fiber (estimated dry matter content) = 3.4%

Red denotes controversial item

Estimated Nutrient Content
Guaranteed Analysis25%16%NA
Dry Matter Basis25%16%51%
Calorie Weighted Basis22%33%45%
Protein = 22% | Fat = 33% | Carbs = 45%

The first ingredient in this dog food is lamb. Although it is a quality item, raw lamb contains about 80% water. After cooking, most of that moisture is lost… reducing the meat content to just 20% of its original weight.

After processing, this item would probably occupy a lower position on the list.

The second ingredient is brewers rice. Brewers rice represents the small grain fragments left over after milling whole rice.

This is an inexpensive cereal grain by-product and not considered a quality ingredient.

The third ingredient lists barley. Barley is a starchy carbohydrate supplying fiber and other healthy nutrients. Unlike grains with a higher glycemic index (like rice), barley can help support stable blood sugar levels in dogs.

The fourth ingredient lists soybean meal. Soybean meal is actually a useful by-product. It’s what remains of soybeans after all the oil has been removed.

Soybean meal contains 48% protein. However, compared to meat, this is an inferior plant-based protein. So, we must allow for this boosting effect as we judge the meat content of this food.

The fifth item is brown rice. Brown rice is a quality ingredient… a complex carbohydrate that (once cooked) is fairly easy to digest.

The sixth ingredient is dried egg product… a dehydrated form of shell-free eggs. Quality can vary significantly. Lower grade egg product can even come from commercial hatcheries… from eggs that have failed to hatch.

In any case, eggs are easy to digest and have an exceptionally high biological value.

The seventh ingredient is lamb meal. Lamb meal is considered a meat concentrate and contains nearly 300% more protein than fresh lamb.

The eighth ingredient is pork fat. Commonly known as lard, pork fat can add significant flavor to any dog food. Though it can be high in saturated oils, in reasonable amounts, pork fat can be considered an acceptable ingredient.

The ninth ingredient is soybean oil… red flagged here only due to its suspected (yet unlikely) link to canine food allergies.

The tenth ingredient is powdered cellulose… a non-digestible plant fiber usually made from cotton or sawdust. Cellulose is sometimes added to dilute the number of calories per serving and to give the feeling of fullness when it is eaten.

Except for the usual benefits of fiber, powdered cellulose provides no nutritional value to a dog.

From here, the list goes on to include a number of other items.

But to be realistic, ingredients located this far down the list (other than nutritional supplements) are not likely to have much of an effect on the overall rating of this product.

With two notable exceptions

First, we find no evidence of probiotics… friendly bacteria applied to the surface of the kibble after processing.

Finally, the minerals here do not appear to be chelated. And that can make them more difficult to absorb. Non-chelated minerals are usually associated with lower quality dog foods.

Hill’s Science Diet Nature’s Best Dog Food
The Bottom Line

Judging by its ingredients alone, Hill’s Science Diet Nature’s Best appears to be an average dog food.

But ingredient quality by itself cannot tell the whole story. We still need to estimate the product’s meat content before determining a final rating.

The dashboard displays a dry matter protein reading of 25%, a fat level of 16% and an estimated carbohydrate content of 51%.

You may have noticed the carbohydrate content reported by Hill’s does not agree with ours. That’s because the computing method1 used by the company is different than the technique we used.

In any case…

As a group, the brand features an average protein content of 27% and a mean fat level of 18%. Together, these figures suggest a carbohydrate serving size of 47% for the overall product line.

Near-average protein. Near-average fat. And average carbs… when compared to a typical dry dog food.

Yet when you consider the protein-boosting effect of the soybean meal, this looks like the profile of a kibble containing only a moderate amount of meat.

Bottom line?

Hill’s Science Diet Nature’s Best is a plant-based dog food using a moderate amount of chicken or lamb as its main source of animal protein… thus earning the brand three stars.


Important FDA Alert

The FDA has announced it is investigating a potential connection between grain-free diets and a type of canine heart disease known as dilated cardiomyopathy. Click here for details.

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Notes and Updates

12/29/2009 Original review
08/05/2010 Review updated
08/12/2011 AAFCO Statements added (company website update)
02/18/2013 Review labeled “Discontinued”

02/18/2013 Last Update

  1. Nitrogen-free extract method