Earlier to day I posted a link to a talk Gary Taubes gave a couple of years ago while promoting his book Good Calories, Bad Calories. This is one of the most popular books amongst the low carb/paleo online community.
Now I would like to say from the outset, that I’m not anti paleo or anti low carb. In fact my own diet is pretty much paleo most of the time. This is because it works great for me, I thrive on it and over 20 years struggling with high carb diets has taught me what works best for me. But I also know a lot of sportsmen that thrive on a diet with lots of carbs. So what’s going on?
Well I think that Gary Taubes is right about a lot of things, and if you haven’t read his book I would encourage you to listen to his talk. I would also say that whist a diet relatively high in carbs can work for some sportspeople, I would say that it’s pretty disastrous for most people who are sedentary, and whether you buy-in to the Grok/caveman, paleo thing I’m pretty sure that most people who are overweight and have struggled to lose weight would be much healthier on a paleo diet.
If every-time you read the words “low-fat” on a food stuff, you substituted the phrase “high sugar” then that would give you a pretty good idea of the problem. Most people think low-fat means low-calorie, which mostly it isn’t and if you don’t do any exercise and you’ve eaten low fat/high sugar versions of food for 40 years, by the time many people start to approach middle age a very large proportion of them will be insulin resistant and would benefit hugely from a high fat, low carb diet.
I would further qualify all this, by saying that whatever diet you are on, lots and lots of fresh vegetables are hugely important.
I think the problem for me is that when it comes to diet people seem to get really polarised. There are the vegans and the vegetarians, there is the low-fat/complex carbs mantra coming from the government and then there’s the low carb, paleo people as well. And in every camp there are a whole load of people who have never felt better and can’t wait to spread the news. So what’s going on?
Well I think the truth is that there is probably no other animal on earth that is as adaptable as man and some people are going to have naturally low levels of insulin resistance and some are not. I’ve personally never tried a vegan diet (I have no moral objection to eating animals) and the kind of sports I do I’m pretty sure need a lot of protein to maximise recovery, but nor am I saying your spine is gonna explode if you try to play the odd game of tennis and decide to you don’t want to eat anything with a face.
So this is really a long preamble to what I wanted to talk about today which is some of the maths behind diet in general. Which is really pretty simple, but often gets overlooked.
The first things I want to say is that is a miracle that we are all not all massively overweight. Here’s what I mean. If I need 3,000 calories to get through my day, how many calories extra would I have to eat to become the fattest man in the world by the age of 50? Lets assume I started at 170 lb at age 20. Well the answer is not very many.
The fattest man in the world is a Mexican called Manuel Uribe who weighs in at 1200lbs (just over 85 stones). The difference between his weight and mine is 1,030lbs and at 3,500 calories per pound that means I would have to eat 3,605,000 extra calories, but over 30 years that is only around 300 extra calories a day. Here are a list of foods that give around 300 calories.
- Mars bar: 294
- Big Mac: 492
- KFC medium fries: 294
- Avocado pear: 275
- 1 small (50 gram) pack of slated peanuts: 311
- Ham and swiss cheese panini: 557
- Chicken breast: 342
Now if I told you that if you eat just one small chocolate bar a day you would end up not just fat, but the fattest person in the world at 1200lbs you wouldn’t take me seriously.
What’s more, if you have ever tried to count calories you’ll know how hard it is to judge a days food/exercise to within 300 calories. Over the years I’ve had various heart rate monitors, plus different pieces of gym equipment that can all give wildly different values for the same exercise. Certainly over the course of a two-hour training session, easily enough to be a 100 or 200 calories out. And yes may be if I cook everything myself and weigh every ingredient I can get to within a 100 calories a day, but as soon as I go to my mum’s for lunch or eat at a restaurant I’ll be lucky to estimate a meal to within 200 calories. So over the course of a week even if I’m being meticulous I’m going to be anything up to a 1,000 calories out.
So how does our body do it? How does it keep us from ballooning massively? I think that obviously Taubs is on to something here and that our hormones must be playing a part in regulating our weight. The fact that even fat people aren’t all the size of Mr Uribe, means that even living off a diet of soda and junk food and sitting on our arses all day our body does a pretty good job of regulating our weight. Obviously if we all ditched the sugar, cut right back on the carbs and took some exercise each day then we would all feel and look a lot better. But then that’s not really controversial. Or is it?
You see a lot of people will listen to Taubs and then say so as long as I don’t eat carbs I can eat what I want. And this isn’t quite true. Sure ingesting lots of carbs makes it easier to store a lot of fat, but even in the absence of carbs if you eat more calories than you burn then your body will use protein to help your body store the fat. Now if you try to live on a diet of no carbs and no protein you’re going to die, for reasons that are to obvious for me to even go into. Anyway, even people on low carb diets are usually eating 100 – 200 grams of carbs a day, more than enough to allow you to lay down excess fat calories as fat.
So it’s not so simple. High carb diets make it easier to lay down fat. Partly because of the hormonal stuff Taubes talks about, and partly because a lot of it is really cheap and really tasty. But for athletes burning a lot of energy, they shouldn’t have the same insulin sensitivity problems that a lot of people get. And for the rest of us, even on low carb/high fat, if you eat too much in the end you will put on weight and at the very least find it hard to shift any excess pounds.