Thanks, I've been waiting for an excuse to discuss the Venus posts.
The basic argument of the posts seems to be that:
- It only takes a couple of spoons of extra fat a day to become obese.
- Eating an extra couple of spoons of fat is easy.
- Therefore, becoming obese eating just fat (and protein) is easy.
But this line of argument completely ignores all the discussions in the paleosphere about caloric intake/expenditure regulation. For any-one who's heard of leptin (and I'm sure Don has), this argument just doesn't seem compelling at all. Why don't animals (or human animals) in the wild, commonly become obese without access to scales and a calorie count, if all it requires is half a mouthful of extra fat per day? (Notably, modern people living a pre-industrial lifestyle, don't seem to be afflicted by such obesity, so the very data that Don seems to be trying to explain seems dubious). The idea that becoming obese is easy, over a long period of time, because all you need to do is eat slightly more than you need regularly assumes that eating slightly more than you need all the time, even as you gain substantial amount of body fat, is easy. This in itself assumes that our bodies don't naturally respond to increased fat mass, making it harder to eat more (which in healthy circumstances they do). The interesting question then (complete ignored) is whether meat and fat are likely to fundamentally disorder your energy regulation, which seems implausible.
As for Don's comparison of fat-based to carb-based meals. I have to report the precise opposite to his claim. In an immediately obvious sense, over-eating low carb, high fat foods seems far harder than over-eating carbs, in my experience. Fat might be 'tasty,' but in my experience it doesn't have the moreish quality that carbs do. However nice a stick of butter might taste, most people find it difficult to eat a lot of it, whereas most people have experienced an urge to eat lots of carbs, once they've started, even if they aren't particularly intrinsically tasty. I'm open, incidentally, to the possibility that some safe paleo carbs, like plain boiled potatoes or white rice, don't have the appetite stimulating effect of bread/pasta- but suffice to say the claim that fat is tastier, doesn't suggest that it's easier to eat a lot of it.
Don's specific arguments for it being easier to overeat fat than carbs also seem astonishingly weak.
“Which do you enjoy more, one 4-ounce
boiled potato (about 100 kcal), or two
tablespoons of cream (also about 100
Sure, but it also seems that the cream is far more satisfying than the equal quantity of potato. I know that I was hungrier eating lots of potatoes (the bulk of virtually every family meal), than I was eating a smaller amount of fat.
“Its obvious which has the higher
I've always been struck by how people (typically mainstream obesity researchers) can cite caloric density as though it's actually meaningful, without exploration. Yes, there's evidence that caloric density is a factor in appetite control, (sheer bulk filling you up, for one), but no reason to think that caloric density is intrinsically important. No-one sits down to a fixed meal of '100g of food' (whatever the caloric density). If this were an over-riding factor, then the obesity problem would be solved by handing out fibre supplements and glasses of water. There are also importantly different sorts of hunger. Eating non-caloric bulk can stop one sort of hunger (probably ghrelin-related), but can't stop sheer my-cells-have-got-no-energy hunger. Back when I was eating lots of plants and few calories, I was full all the time, but over the long term the body isn't fooled and you want to actually consume some macronutrients.
And yes, there is a slight metabolic advantage, in the sense he discusses, from eating carbohydrate. The interesting question therefore is whether there are any other factors advantaging fat intake- for example, slower digestion, lower insulin. My general suspicion is that our bodies aren't so easily I fooled. Knowing that carbs have this 10% advantage, it seems implausible that our bodies haven't evolved to take this into account in deciding how much food we need. If so, we should not expect that people find it intrinsically easier to overeat fat than carbs.
“I've never met a person who binges on
Actually, I thought it was widely acknowledged that carbs were the primary binge food. I don't know any-one who binges on tallow either. I'm sure boiled potatoes specifically aren't a common binge food, but see no reason to think that people wouldn't binge on plain carbs, rather than carbs+fat.
I'm not interested in contesting Don's denial that “carbohydrates make people fat,” since no-one, not even Taubes, claims that carbohydrates necessarily make people fat. What is being contested here, is the idea that it's very difficult to get substantially fat eating just meat and fat.
Of course, the other major assumption of Don's post is that the Venus actually represents an obese, solely meat-eating woman, who needs to be explained. It seems perfectly plausible that the sculpture serves some other purpose- the sculpture just looks like an exaggeration rather than an attempt to accurately capture an actual woman's body shape.