Eggs & dairy 18 . Cage-free eggs 19 . Full-fat unsweetened yogurt or kefir 20 . Raw whole milk 21 . Hard cheese , sour cream and heavy cream ( all are low in carbs , but very importantly I recommend grass-fed and organic dairy whenever possible , ideally made from raw milk ). Cheeses low in carbs include blue cheese , cheddar cheese , goat , feta , Swiss , parmesan and asiago .