“Only food that can be easily digested will provide calories”
That statement would seem to also be obviously wrong. Plenty of things are ‘easily digested’ in any reasonable meaning of that phrase, while providing ~0 calories.
I think you’ve interpreted this backwards; the claim isn’t that “easily digested” implies “provides calories”, but rather that “provides calories” implies “easily digested”.
Well, debates about what modal operators are meant by ‘only’ aside, I am doubtful that claim is true either! First, as a parallel consider grass again: to digest grass, ruminants need an extremely long intestinal system which takes multiple passes (including throw it up to the mouth to chew it again, for hours on end, chewing their cud again and again) and requires tons of microbes to digest it over multiple days; again, under any ordinary understanding of the phrase ‘easily digested’, it is not easy for cows to digest grass. Yet they still get all the calories they need to live on from it. So, for cows, grass ‘provides calories’ and yet is not ‘easily digested’. This is also true for humans: eating plants and raw uncooked foods ‘provide calories’, but are not ‘easily digested’; in fact, they provide much less net calories than they should because so many calories go right back into the digestive process.* (And this is one of the major theories for the importance of fire & cooking in human evolution: ‘the expensive gut tissue’ hypothesis.) You could also point to things like ‘poisonous berries’: you eat them and enjoy calories as their simple carbohydrates easily digest… until you then lose a bunch of calories by being sick and sh−ting yourself all day long. Easily digested, without a doubt but did they provide calories? They did—but only for the first few hours. So, this brings out that when you talk about ‘easily digested things’ which ‘provides calories’, you are implicitly including the caloric costs of digestion & side-effects and it’s really net calories you are talking about. Which will also be context-specific (eg. presumably there are wild animals like birds who will be immune to the berry poison and are the intended consumers, and for them the berries deliver full caloric value).
* see also: the malnourishment of ‘raw foodists’, which manifests in symptoms like menstruation stopping.
I think you’ve interpreted this backwards; the claim isn’t that “easily digested” implies “provides calories”, but rather that “provides calories” implies “easily digested”.
Well, debates about what modal operators are meant by ‘only’ aside, I am doubtful that claim is true either! First, as a parallel consider grass again: to digest grass, ruminants need an extremely long intestinal system which takes multiple passes (including throw it up to the mouth to chew it again, for hours on end, chewing their cud again and again) and requires tons of microbes to digest it over multiple days; again, under any ordinary understanding of the phrase ‘easily digested’, it is not easy for cows to digest grass. Yet they still get all the calories they need to live on from it. So, for cows, grass ‘provides calories’ and yet is not ‘easily digested’. This is also true for humans: eating plants and raw uncooked foods ‘provide calories’, but are not ‘easily digested’; in fact, they provide much less net calories than they should because so many calories go right back into the digestive process.* (And this is one of the major theories for the importance of fire & cooking in human evolution: ‘the expensive gut tissue’ hypothesis.) You could also point to things like ‘poisonous berries’: you eat them and enjoy calories as their simple carbohydrates easily digest… until you then lose a bunch of calories by being sick and sh−ting yourself all day long. Easily digested, without a doubt but did they provide calories? They did—but only for the first few hours. So, this brings out that when you talk about ‘easily digested things’ which ‘provides calories’, you are implicitly including the caloric costs of digestion & side-effects and it’s really net calories you are talking about. Which will also be context-specific (eg. presumably there are wild animals like birds who will be immune to the berry poison and are the intended consumers, and for them the berries deliver full caloric value).
* see also: the malnourishment of ‘raw foodists’, which manifests in symptoms like menstruation stopping.