A dietitian reveals the best high-protein, high-fiber Costco bulk foods for weight loss.

Everyone I know shops at Costco, even nutritionists and dieticians. While the warehouse sells a lot of high-calorie items, including almost everything from the famous bakery, there are plenty of healthy options too. My go-to nutrition expert, Tara Collingwood, MS, RDN, CSSD, LD/N, ACSM-CPT, a Board Certified Sports Dietitian and co-author of the Flat Belly Cookbook for Dummies, is one of the millions of Costco members who shop at the store. She recently shared her bulk shopping list with me. “I like this list overall because it focuses on nutrient-dense, minimally processed foods, which are exactly what we look for when supporting weight loss. But it’s important to remember: no single food causes weight loss. These foods work because they help with satiety, blood sugar control, and overall diet quality. Even healthy foods like nuts, almond flour, and seeds are calorie-dense, so portion size still matters. Weight loss ultimately comes down to overall calorie balance, not just choosing ‘healthy’ foods,” she says. “For weight loss, I focus on foods that are high in protein, fiber, and healthy fats because they help keep you full longer and reduce overeating. Buying these in bulk can also make it easier to stick with healthy habits.” Here are 9 Costco bulk foods dieticians swear by for weight loss.

Kirkland Organic Greek Yogurt

Costco

Kirkland Organic Greek Yogurt is always recommended by health and fitness experts. “High in protein, which helps with fullness and preserving lean muscle during weight loss,” she says. “Note: It’s not ‘zero sugar’ because it contains natural lactose, but it is zero added sugar.” An added bonus? It is creamy and delicious.

Kirkland Shelled Hemp Hearts

Costco

She is also a fan of Kirkland Shelled Hemp Hearts. “Provide healthy fats, some protein, and minerals. Fats help with satiety, but portion size matters since they’re calorie-dense,” she says.

Wild Caught Sockeye Salmon

Costco

Wild Caught Sockeye Salmon is another one of her go-to buys. “Rich in protein and omega 3 fatty acids, which may support heart health and help with satiety. A great option for balanced meals,” she says. And, at Costco you will save big by buying it in bulk.

Kirkland Almond Flour

Costco

If you like to cook, consider Kirkland Almond Flour. “Lower in carbs than traditional flour and contains healthy fats and some fiber, but it’s still calorie-dense, so it’s not inherently ‘weight loss friendly’ unless portions are controlled,” says Collingwood.

Rotisserie Chicken

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Several shoppers buy more than one of Costco’s famously cheap $5 rotisserie chicken. “A convenient, high-protein option that can make meal prep easier. Removing the skin can reduce saturated fat and calories if needed,” she says.

Kirkland Frozen Organic Berries

Costco

Another item that most health experts buy, especially for adding to protein shakes and smoothies? Kirkland Frozen Organic Berries. “High in fiber and antioxidants with no added sugar. Fiber helps with fullness and blood sugar control, making them excellent for weight management,” she says.

Kirkland Boneless Chicken Breast

Costco

And, Kirkland Boneless Skinless Chicken Breast has been a warehouse bestseller for decades. “A staple lean protein that is high in protein, low in fat, and very versatile. Supports satiety and muscle maintenance,” she says.

Kirkland Walnuts

Costco

Kirkland Walnuts are one of the most popular nuts. “Contain heart-healthy fats and some fiber, which can help with fullness. Like all nuts, they’re nutritious but calorie-dense, so portion awareness is key,” says Collingwood.

Season Brand Sardine Fillets

Costco

Season Brand Sardine Fillets are another heart-healthy option. “Packed with protein, omega-3s, and calcium (especially if bones are included). Very nutrient-dense and satisfying,” says Collingwood.

Leah Groth

Leah Groth is an experienced shopping editor and journalist for Best Life and Eat This, Not That! bringing readers the best new finds, trends, and deals each week. Read more about Leah