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

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.
Season Brand Sardine Fillets

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
