Real cooks know better." Second, he's lecturing Americans on their diet when there are still fat people in England? The nerve!
The response to the first argument seems obvious. Sure, if you have the time, money, knowledge and resources you can create a better meal experience with a few hours of work than you're likely to get from one of Jamie's recipes. But let's be honest here: Oliver's not trying to compete with you or with a quality restaurant experience. He's trying to compete with packaged foods like Hamburger Helper and Rice-a-Roni, and take-out from places like McDonalds and KFC. By all means, take the whole day to prepare a healthy feast for your family, but let's not pretend that the majority of people have that luxury or that, even if they had the time, kitchen gadgets, ingredients and knowledge, that it would be their priority.
The second criticism represents a failure of logic, and I'll admit that I picked the low-hanging fruit from the linked article. Oliver is trying to guide British people toward healthier food choices, but even if he weren't his comments as directed toward the U.S. market wouldn't be any less valid. Besides, he's getting very rich in the process - so let's embrace his criticism as part of the American way. ;-)
The more serious argument raised in the "who's a Brit to tell us how to eat" article is that the primary cause for the change in our waistlines comes not from diet but from inactivity. I think it's fair to say that's part of the cause - even as we eliminate recess from elementary school days and open charter schools that have no athletic or exercise facilities, we complain that kids don't spend enough time playing outside. Heck - it wasn't so long ago that you had to walk your type document over to the copier, and distribute copies into co-workers' mail boxes - not a lot of exercise, but at least you had to get up and move a little bit. In most workplaces you can achieve those same tasks more quickly and efficiently without leaving your desk chair. Yes, society is a lot more sedentary than was historically possible.
But it oversimplifies things to argue that "If you're working twelve-hour shifts at the car plant, you can eat whatever you want." It's not just blue collar workers who are heavier than their historic peers. Nor were all blue collar workers historically recognized for their slim waistlines. The reality is, we've moved as a society toward packaged and prepared foods. Thanks to corn subsidies we have food that's full of corn, corn syrup, and fatty beef - and it's cheap. Restaurant portions, including fast food portions, have grown substantially in size over the years. Yes, when McDonalds introduced its fries in 1955 they weighed 68 grams, the same as a modern "small fries" - but the "small" size is what we now feed to our kids. An 1955 soda was 207 mL. A child's soda is now 354 mL. Last time I went to a movie, the large popcorn bucket was approximately the size of a battleship. (I exaggerate only slightly.) It's pretty easy to get a large soda that's a liter or more in volume - five or more times the amount offered in 1955.
There's also profit in upselling. How much money do you suppose McDonalds has taken in over the decades with its simple question, "Would you like fries with that?" How many times have you been asked a similar question - "Would you like a large? It's only 25 cents more." Meanwhile, behind the scenes, "test kitchens" that are really sophisticated laboratories attempt to determine what flavors, odors and colors are most likely to make you crave more, buy more, eat more, and your packaged, prepared and fast food purchases are engineered accordingly. We eat more than we used to eat, and it's in no small part by design. (Another example of capitalism at work.)
You want to lose weight? Eat less, exercise more. Or 'simply' eat less. But our food culture isn't going to make it easy for you.