You can survive in good health for a long time on only potatoes.
I can't remember where I read it, but I read that to survive for a period of years on potatoes and milk alone, you'd need to eat something like 4kg of potatoes and two gallons of milk a day - which is going to be difficult to carry on a bicycle, at least.
This is an interesting article about losing pack weight. I would avoid tinned anything because it tends to be overly heavy (the weight of the tin plus the weight of the liquid that you throw away) - dried sausage has a better calorie/weight ratio than tinned tuna (plus there are so many delicious regional varieties in France and Spain you'd be daft not to try them anyway). An emergency jar of peanut butter will get you out of trouble if you end up dinnerless one evening.
I can't remember where I read it, but I read that to survive for a period of years on potatoes and milk alone, you'd need to eat something like 4kg of potatoes and two gallons of milk a day - which is going to be difficult to carry on a bicycle, at least.
This is an interesting article about losing pack weight. I would avoid tinned anything because it tends to be overly heavy (the weight of the tin plus the weight of the liquid that you throw away) - dried sausage has a better calorie/weight ratio than tinned tuna (plus there are so many delicious regional varieties in France and Spain you'd be daft not to try them anyway). An emergency jar of peanut butter will get you out of trouble if you end up dinnerless one evening.