You can't eat a classic trail mix from the grocery store because it always contains dried fruits or chocolate. Both of these ingredients are loaded with carbs, sugar and raise blood sugar levels. As a result, on a keto diet, a trail mix from the store can take you out of ketosis. However, if the trail mix you bought is made of raw nuts - not roasted in sugar - then you can sort out the trail mix and only eat the nuts! Discard the dried fruits and chocolate that are the issue in trail mix bags.