Thanks so much for the article, it is very illuminating. Thanks also for the rebuttal of David Freedman's counterpoints. As an academic and researcher, I know how much dedication it takes to develop clear and cogent rebuttals. It is so terribly important that these debates occur.

I would add something that I don't believe you said above, in response to David. Even he concedes that people lose weight on low-carb diets and it is falling off the diets that is the major problem. This is scarcely any way to argue that low-carb isn't desirable!

Yes, in the 'real world' it is important that people continue with the dietary plan. The trouble is that in the real world, people are bombarded with low-fat messages and for that reason alone they will start to doubt. I'd like to see proper studies of the *reasons* that people 'fall off the diet. Is it because they craved carbs after a long period, or due to other forces? There are literally carbs everwhere: I struggle to find good sources of fat.

Again, thanks so much for the article. I have long known of the evidence that fat retards the digestion of carbs, but it tends to get lost.

I have been reading a few comments here and decided to go ahead and post. I was brought up in a home, where my parents tried their hand at getting me to eat veggies. Well, they of course are not the best tasting when you are a kid. I rebelled with their effort. As a kid though, I was not overweight at all. And then I hit puberty. I started putting on weight left and right. I had tried diets later in my early twenties and I tried a lot of them. I had finally become insulin resistant which is a growing epidemic. It almost seems as though, this is the way they are trying to depopulate the world in a slow and painful death. Because of the high sugar I had also developed PCOS. Which has a whole host of it's own issues. I have dieted and exercised in the past where I was mowing lawns about 40-50 hours a week and then working out in a gym, three times a week. So in one year, you would think I would be picture perfect. But, that was not the case. By the end of one year eating to what I thought was perfectly healthy, primarily vegetarian, doing all of that exercise and I lost a total of 50 lbs!!! I was also miserable. Well, imagine my surprise that I could not keep that up any longer. So until recently when someone shared with me a book written by a dietician that had undergone some of the same issues even though she ate perfectly healthy and maintained a perfect weight for most of her life, she all of a sudden started to develop something they have now called Metabolism B. Which all makes sense. I have been on the diet now for a month and a half and have lost 18 pounds of pure fat. It has changed my life and my vitals. My pule has dropped from the 90+ range to sometimes in the 60's. The sugar has dropped also. It is amazing, what it has done for me. And it seems the more nuts and food allowed on the diet I eat the more I lose. So it actually encourages you to eat more. I have not been doing much in the way of exercise here lately as I injured my foot. But, even still?? For me in the past when i set out to lose a pound I would gain three. I have a ton of lean muscle tissue (thank goodness. I do not look as heavy as I actually am.) But, I look at people now in a whole new way. I so badly want to tell them about what I have been doing. It would change their lives! But, I am not mean. I am not judging them I just want to help them. I realize they have to want to help themselves, but, all of the industry is not helping those people that do have what I have and it is only getting worse. the population is much higher than previously thought. I will continue to work on my diet. It looks like I have lost 30 + pounds because it is all fat tissue. I am getting a flat stomach. Like holy crap!! I feel great and love to share it with the world. Changed my life!!

David H. Freedman : Your argument is instantly invalid when you're comparing people eating veggie pizzas vs "supreme" pizzas. At no point in this article does the author say "calories are irrelevant". Of course if you eat 4000 calories a day and you're sitting around on your computer you're going to get fat.

ANYONE eating any sort of take-away pizza is going to get fat unless they're very very active. A large pizza has about 2000 calories then with your coke on top you're nearing 2300-2500. Have another nice fatty desert and you're up to 3000. You can't do that then say "Oh, this proves that fat makes you fat".

I eat lots of fat and I'm 8% body fat. A typical meal for me would be 2-3 scrambled eggs with some goat's cheese and a cup of goat's milk, some chicken+rice+cheese sauce+some cream cheese on the side, peanut butter on bread etc. If I sat eating huge pizzas covered in enough cheese to feed an army of mice while telling myself it's ok because it's fat then I'd be obese.

This is one of the primary problems with people, they eat FAR TOO MUCH FOOD. People are eating as much food as full time athletes and they try all sorts, low carb, low fat and find nothing works because they're stuffing their faces full of stuff all day.

The issue here is that it's easier to stay lean, happy, satiated and full of energy with more fat in your diet, but you still have to eat small portions in accordance with your physical activity. I personally only eat about 2000 calories a day if I'm not training. For most men 2500 calories is too much if they're siting at their computer all day yet most eat 3000+.

People just eat food as a comfort and out of boredom. That's the primary issue. The low fat thing just makes that existing problem that much worse, but this is the reason why simply adjusting the composition of your diet isn't that useful unless you stop eating like a horse.

When I was in College learning about digestion I recall two pictures one of a simple carbohydrate and one of a complex. (this was a long time ago so the details are sketchy). The simple carb was a line of simple sugars joined up in a line with two points of digestion(breakdown?, the beginning and the end. The complex carb was multi chained diagram of simple sugars joined together with MANY points of digestion(breakdown?). I couldn't see how the carb with two points of digestion could be broken down quicker the the one with many points. What I was taught didn't make sense from the diagrams I was given. I concluded that complex meant the shape was more complex, nothing else.

I hope it makes sense I am NOT a writer.

I am confused. I like what you say. It sounds good. I live in NZ and like many Australasians I am fat, and I need help but there is soooo much information,I'm getting confused and I feel overwhelmed-its as if as soon as I hear one new helpful thing I forget some other helpful thing. My question is this: will reducing wheat in my diet reduce the amount of fat on my body (particularly around my belly) and/or give me more energy and a better grip on my moods? Also, what is the best flour out there for me to made bread with if I am not going to use wheat? I'm sorry if you have answered these questions already-I think wheat is making my thinking foggy and my concentration poor so I may have missed it!

Keep going on your crusade-you have got my attention!

A good, clear read. Thank you.

At only 20 years old, I've recently turned to scientific research to learn that dietary fat does not make people fat, does not cause heart disease, and does not play any role in the numerous problems that the general public assume it to cause.
I had thought that the rising rates of diabetes was due to carbohydrate consumption. This has made me realise that it is not only carbohydrate consumption, but just as importantly, fat reduction.

I'm currently unable to leave my house (I basically leave my bed only for meals) due to a severe chronic illness. Because I'm sedentary, most would think that I would pile on weight (and I have in the past). But recently, I changed my diet to eat as much fat (and protein) as I desire, and no grains (or potatoes), so now I'm able to maintain a very healthy weight. Note that the condition I have does not cause weight loss!
I'm very excited to go on to study dietetics once I have recovered! But I'm sure this will be challenging with the current beliefs of the education systems...