Geoff it's the total amount of carbs you want to look at for mayonnaise. If it's below 5% and preferably below 3% carbs then it's low carb. We don't need to distinguish between carbs from sugar and carbs from starch. In fact, technically carbs from sugar would be less bad than carbs from e.g. pasta because they're 50% fructose and 50% glucose rather than 100% glucose. But then we get into a can of worms about how bad is lactose in milk and how fructose causes fatty liver and... it's much easier just to look at the total amount of carbohydrate in a food.
Where you want to look closely at the ingredients is to see how processed a food is. As a rule of thumb if a food has ingredients that you wouldn't use yourself in the kitchen then it's processed. In the case of Hellman's mayonnaise the ingredients are:
Rapeseed oil (78%), water, free range pasteurised EGG and EGG yolk (8.9%), spirit vinegar, sugar, salt, lemon juice, antioxidant (calcium disodium EDTA), flavouring, paprika extract.
The only thing that you wouldn't find in a kitchen is the antioxidant and I'm guessing they have to add that in to make it shelf stable. So I would say this is a pretty good choice for Bootcamp. Yes it's better to make your own mayo but we don't all have the time/resources/ability to do that and anyway Hellman's tastes better than my homemade mayo!-