Welcome to our review of Diamond Naturals Grain Free Dog Food.

Diamond Naturals Grain Free Dog Food Review

Name: Diamond Naturals Grain Free Dry Dog Food
Item: Diamond Naturals Grain-Free Chicken & Sweet Potato Formula
Rating: 4.53
Author: Samuel James

Disclosure: As a Chewy affiliate, we earn commissions for qualifying purchases.

List of products

Diamond Naturals Grain Free Products	Ratings	AAFCO
→ Diamond Naturals Grain-Free Beef & Sweet Potato Formula	4.4	All Life Stages
→ Diamond Naturals Grain-Free Chicken & Sweet Potato Formula	4.6	All Life Stages
→ Diamond Naturals Grain-Free Whitefish & Sweet Potato Formula	4.6	All Life Stages

This dog food line has 3 recipes. Reviewing all isn’t possible. The review of Chicken & Sweet Potato Formula shows the quality, nutrition, and composition of the whole line.

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Ingredients

Chicken, chicken meal, sweet potatoes, peas, lentils, pea flour, chicken fat (preserved with mixed tocopherols), dried tomato pomace, natural flavor, fish meal, flaxseed, salmon oil (source of DHA), salt, DL-Methionine, choline chloride, taurine, dried chicory root, yucca schidigera extract, tomatoes, blueberries, raspberries, dried Lactobacillus plantarum fermentation product, dried Bacillus subtilis fermentation product, dried Lactobacillus acidophilus fermentation product, dried Enterococcus faecium fermentation product, dried Bifidobacterium animalis fermentation product, vitamin E supplement, iron proteinate, zinc proteinate, copper proteinate, ferrous sulfate, zinc sulfate, manganese sulfate, copper sulfate, potassium iodide, thiamine mononitrate, manganese proteinate, ascorbic acid, vitamin A supplement, biotin, niacin, calcium pantothenate, sodium selenite, pyridoxine hydrochloride, vitamin B12 supplement, riboflavin, vitamin D3 supplement, folic acid.

Ingredient Analysis

The first five ingredients are highlighted as the primary ingredients in this review of Diamond Naturals Grain Free Dog Food.

Primary Ingredients

→ Deboned chicken is a high-quality protein used in premium dog foods. It’s made by removing the bones from fresh chicken, leaving nutrient-rich meat. It supplies essential amino acids for muscle maintenance and energy, and it’s easy to digest.

However, since chicken is a common allergen, it may not suit pets with poultry sensitivities.

Deboned chicken (raw, skinless) provides about 22.5 grams of protein per 100 grams.

→ Chicken meal is rendered chicken meat that has been dried and ground, and it typically includes clean flesh, skin, and bone.

It has a higher protein concentration—approximately 65%—compared to deboned chicken, making it beneficial for muscle development.

Additionally, chicken meal is a natural source of glucosamine, a key component in supporting cartilage and joint health.

→ Sweet potatoes are a starchy, nutrient-dense root vegetable prized for their sweet flavor and versatility. They provide fiber and steady energy, support eye and immune health with beta-carotene, and are a rich source of vitamins, minerals, and antioxidants.

Each 100 g of raw sweet potatoes (without skin) contains approximately 17.3 g of carbohydrates and 4.44 g of fiber.

→ Peas are a common part of commercial pet foods. They provide fiber, vitamins (A, C, K), minerals (iron, manganese, phosphorus), and antioxidants.

Raw green peas have 5.42 g of protein and 14.4 g of carbohydrates in each 100-gram serving.

→ Lentils are a common ingredient in many commercial dog foods, particularly as a grain-free alternative to traditional carbohydrate sources like rice or corn. They provide pets with polyphenols, protein, iron, fiber, folic acid, and magnesium. Each 100 g of dry lentils contains about 23.6 g of protein and 62.2 g of carbohydrates.

Secondary Ingredients

The three ingredients immediately following the primary ingredients are highlighted as the secondary ingredients in this Diamond Naturals Grain Free Dog Food Review.

→ Pea flour is made from dried, ground peas and serves as a plant-based source of protein, fiber, and carbohydrates. It is used as a grain-free alternative and as a binder in kibble and treats. It is produced by removing the hull and pod before roasting or milling the peas, and it retains much of the nutritional profile of whole peas.

→ Chicken fat is the fat separated from chicken tissues during rendering. It is commonly used in dog food as a concentrated energy source and flavor enhancer.

It is rich in omega-6 fatty acids, such as linoleic acid, and is often preserved with mixed tocopherols to maintain freshness.

→ Tomato pomace is a byproduct of processing tomatoes into products like sauces, ketchup, juices, purees, and concentrates.

It consists of the dried and ground skins, pulp, and crushed seeds of tomatoes. It provides soluble fiber and the antioxidant lycopene.

Other Ingredients

→ Natural flavor is an ingredient derived from plant or animal sources used to enhance taste and palatability.
It is commonly added to pet food to make it more appealing to dogs and may be sourced from herbs, meats, or concentrated extracts of animal products.

→ Fish meal is a concentrated protein source made by cooking, drying, and grinding fish (often whole fish or leftover parts) into a powder.

It retains many benefits of whole fish, like omega-3 fatty acids for healthy skin and fur, but its quality depends on the fish species and its processing method.

→ Flaxseed is a natural source of omega-3 and omega-6 fatty acids that help keep skin healthy, make coats shiny, and reduce inflammation in dogs.

Every 100g of ground flaxseed contains around 18g of protein, 37.3g of fat, 34.4g of carbs, and 23.1g of fiber.

The Chicken & Sweet Potato Formula includes other beneficial ingredients further down the list to support your dog’s health. However, we won’t explore them in detail here due to the scope of this Diamond Naturals Grain Free Dog Food Review.

Nutrient Sources - Diamond Naturals Grain Free Dog Food

Nutrient	Sources
Protein	Chicken, Chicken Meal, Sweet Potatoes, Peas, Lentils, Pea Flour, Dried Tomato Pomace, Fish Meal, Flaxseed
Fat	Chicken, Chicken Meal, Lentils, Chicken Fat, Dried Tomato Pomace, Fish Meal, Flaxseed, Salmon Oil
Carbohydrate	Sweet Potatoes, Peas, Lentils, Pea Flour, Dried Tomato Pomace, Flaxseed, Tomatoes, Blueberries, Raspberries
Fiber	Sweet Potatoes, Peas, Pea Flour, Dried Tomato Pomace, Flaxseed, Tomatoes

Vitamins

This dog food contains a comprehensive spectrum of essential vitamins, including A, D3, E, and the B-complex (thiamine, riboflavin, niacin, B6, B12, folic acid, biotin, and pantothenate).

Vitamin C is added as ascorbic acid. Vitamin K is absent but is synthesized by a dog’s body and derived from ingredients like tomatoes and peas. The vitamins are primarily synthetic, which ensures precise dosing and stable shelf life.

The formula appears nutritionally sound for adult dogs, with no significant adequacy gaps.

Minerals

Critical macro-minerals like calcium and phosphorus are absent from the supplement list, relying solely on whole ingredients. While chelated trace minerals (iron, zinc, etc.) offer excellent bioavailability, the lack of guaranteed calcium and phosphorus levels is a significant adequacy gap for bone health.

Although some calcium and phosphorus may be present in ingredients present in the list.

Ingredient Concerns

This recipe overall appears nutrient-dense, but several broad concerns are worth noting.

First, calcium and phosphorus are not explicitly included as standalone ingredients. However, since the product is labeled complete and balanced for all life stages, adequate calcium and phosphorus levels are assured from ingredients like chicken, chicken meal, and fish meal despite not being individually listed in the ingredient panel.

The practice of “ingredient splitting” where these plant-based ingredients are listed separately, may obscure the fact that they collectively could outweigh the animal protein sources, making the food less meat-based than it initially appears.

The recipe uses some highly bioavailable chelated minerals but also includes less absorbable inorganic forms, and the vague term “natural flavor” lacks transparency.

Common allergens such as chicken, peas, lentils, and fish may also pose issues for sensitive dogs.

This Diamond Naturals Grain Free Dog Food Review highlights both the strengths and potential concerns in the formulation, giving pet owners a clearer picture of what to expect from this popular dry dog food line.

Nutrient Analysis

Moisture=10% Max

Method of Analysis	Protein	Fat	Carbs	Fiber
→ Guaranteed Analysis	24%	14%	39%	5%
→ Dry Matter Basis	26.7%	15.6%	43.3%	5.6%
→ Calorie Content Basis	24.7%	35.1%	40.2%	NA

Normal dog food typically contains (18-35)% protein, (30–50)% carbohydrates and (9–25)% fat on a dry matter basis.

However, Chicken & Sweet Potato Formula contains 26.7% protein, 15.6% fat, and approximately 43.3% carbohydrates on a dry matter basis.

This makes it Moderate in protein, Moderate in fat, and Moderate in carbohydrates.

Compliance with AAFCO and FEDIAF Standards

The Chicken & Sweet Potato Formula contains 26.7% protein and 15.6% fat on a dry matter basis.

These levels exceed the minimum requirements for both adult maintenance and growth and reproduction, as set by AAFCO and FEDIAF standards, ensuring the food provides sufficient protein and fat to support your dog’s overall health.

Every recipe in Diamond Naturals Grain Free Dog Food line meets AAFCO and FEDIAF standards.

AAFCO Statement

“Diamond Naturals Grain-Free Cage-Free Chicken & Sweet Potato Formula for Dogs is formulated to meet the nutritional levels established by the AAFCO Dog Food Nutrient Profiles for All Life Stages including growth of large size dogs (70 lb. or more as an adult).”

The statement indicates that the recipe meets AAFCO nutrient requirements based on laboratory nutrient analysis, but it does not confirm that the food has undergone AAFCO-approved feeding trials.

Lab analysis verifies that the nutrient levels meet the required standards on paper, whereas feeding trials demonstrate real-world performance in dogs, including digestibility, palatability, and overall health outcomes.

Cost Analysis

Cost Metrics	5-lb bag	14-lb bag	28-lb bag
→ Cost per Unit	$15.99	$31.99	$51.99
→ Cost per Pound	$3.20	$2.28	$1.86
→ Cost per Serving	$0.83	$0.60	$0.48

The table shows steeply diminishing unit costs as bag size rises: the 5-lb bag is cheapest up front but costs $3.20/lb and $0.83 per serving, while the 14-lb and 28-lb options drop to $2.28/lb ($0.60/serving) and $1.86/lb ($0.48/serving) respectively.

Buying larger sizes clearly reduces long-term feeding costs for Diamond Naturals Grain Free Dog Food, but larger bags require more storage, risk staling for small-household or picky dogs, and tie up cash.

If you use the food regularly and can store it properly, economies of scale favor the big bag. Otherwise the 14-lb is a reasonable middle ground.

The 28-lb bag is the best overall value.

Chewy Autoship offers 35% off (up to $20) on your first order. For a 28-lb bag, the cost is $51.99, but on Autoship, it drops to $33.79, saving $18.2.

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Note: Prices are subject to change based on retailer, location, and availability.

Pros and Cons - Diamond Naturals Grain Free Dog Food

Pros

Includes Probiotics for Digestive Health
Features Omega Fatty Acids for Skin and Coat
Antioxidant-rich fruits & vegetables
Prebiotic fiber and digestibility supports
Grain-free formulation

Cons

Ingredient splitting can be seen
High legume content
“Natural flavor” and “fish meal” are vague and lack transparency
Contains common allergens like chicken

Recalls and Safety

The most significant Diamond Dog Foods recall occurred in 2012 after Salmonella Infantis linked to their Gaston, South Carolina plant prompted large, multi-brand recalls.

Diamond also issued a separate voluntary recall in 2013 for limited cat-food production codes because of possible low thiamine levels, which remains the most recent recall for this brand.

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Our Rating

Our dog food rating system rated the Chicken & Sweet Potato Formula at 4.6 out of 5, while the Diamond Naturals Grain Free Dog Food line received an overall rating of 4.53 out of 5.

Final Verdict

This article gives a basic look at dog food ingredients, but you should always ask your vet for specific advice. Your dog may have different needs, and an expert’s help is important.