The World Health Organization predicts there will be 2.3 billion overweight adults in the world by 2015 and more than 700 million of them will be obese. Figures for 2005 show 1.6 billion adults were overweight and 400 million were obese. That’s a forty percent increase in just 10 years, at a time, where heathy living has never had a higher profile in the media. Obesity is a new problem. My grandparents generation didn’t worry about it. Of course there have always been a few fat people, not the kind of epidemic we have today. Yet there has never been so much diet advice and still people keep getting fatter and fatter. Why? One reason is this kind of thing, here’s an except from a recent article on the diet of Jessica Ennis:
What’s a typical breakfast for you?
I’ll have a bowl of Bran Flakes with fruit juice and maybe an organic flapjack or a piece of fruit.
What and when do you tend to snack on during the day?
It all depends on how long my training sessions are but I tend to have a cereal bar, banana or apple in between them.
What do you eat for lunch?
I have a ham or turkey salad sandwich and some more juice or a recovery drink.
What is your favourite dinner and dessert?
I eat a lot of red meat like beef which, as an athlete, is good for iron. So I’ll probably have chilli or lasagne or stir-fries. I always have dessert. I usually go for something chocolatey.
Nothing wrong with this diet for a full-time athlete like Jessica Ennis burning thousands of calories a week training, but how many people will be reading that and thinking, if I eat like Jessica, I’ll look like Jessica?
The truth is that there’s a world of difference between the dietary requirements of top sports people and the general population. Yes of course a premiership footballer needs a nice a nice big bowl of pasta for lunch, he’s just spent two hours running around the training pitch and is probably still recovering from running 7 – 10 miles during the weekends game. For most people living pretty sedentary lives, too many carbs are just going to make you fat.
Most people need a lot less carbs than they think.
Carbs are needed to keep up high intensity excise. So for sitting in front of the TV or wandering around the shops or the office, our bodies just don’t need them. To understand this lets compare what happens when we eat a high carb meal.
First lets look at a top athlete.
As they start to excise harder their body’s muscles can no longer provide all the energy they need aerobically. During aerobic exercise our bodies convert fat into energy, the problem is that the chemical process that takes place is quite slow and as exercise intensity increases our energy needs exceed what can be supplied aerobically. At this point we need a new (faster) fuel source. This is where the anaerobic energy pathway comes in, burning glycogen stored primarily in our muscles to create the energy needed. After prolonged anaerobic exercise our body needs to replenish the glycogen used and the only way to do this is to convert carbohydrates. However, producing energy aerobically needs uses a lot of oxygen, which is why as we exercise harder we get out of breath and as a result only very fit people can burn a significant amount of muscle glycogen. Most people can only keep this level of activity up for a short time and so are only able to burn a relatively small amount of glycogen.
What happens when the general population eat a high carb diet.
The short answer is a type 2 diabetes and an obesity epidemic. This is because as we eat a carbohydrate rich meal our body produces insulin which converts the carbs into glycogen, but if our muscles are already full of glycogen because we haven’t used it up since our last carb rich meal, then it is converted to fat and stored. This is OK, once in a while, but this process puts quite a heavy strain on our bodies, causing inflammation which in turn causes plaque to form in our hearts and arteries. Over time, if we repeatedly overload our system with carbs it doesn’t need, it initally becomes insulin resistant and then eventually develops full-blown diabetes. Of course along they way we store all that fat which makes us fat.
Now that’s a very simplistic way of looking at it, so I need to add a couple of caveats.
The first one is that glycogen isn’t just stored in our muscles it’s also stored in our liver.
The second is that what I have just described is how the body stores excess calories. If you are not meeting your daily calorie needs then much of this isn’t applicable.
The third is that our bodies will use the fuel in our bloodstream (fat and glycogen) roughly in the proportion it is available. What this means is that if you eat a sugary meal and flood your blood stream with sugar, then you will burn sugar not fat. This has big implications for people looking to lose fat, because the glucose in their bloodstream stops them burning off the fat they want to get rid of. Insulin is the body’s response to eating carbs and insulin is also the bodies most powerful storage hormone. You can’t burn fat if you have insulin in your bloodstream.
Low fat diets and athletes
The “fat is bad” message is then reinforced by athletes who by-and -large are on a low fat diets. Let me explain.
Most athletes can not afford to put on too much weight, this is pretty obvious. Most sports require either power or stamina. For example to successfully head a ball Wayne Ronney needs to be able to jump higher than the other players around him. This is of course is mainly to do with skill and timing, but also to do with his power to weight ratio. If he puts on a lot of weight he obviously can’t jump as high. For distance runners, carrying extra fat is clearly going to slow them down and be a disadvantage.
Hard training breaks down muscle. Muscle contains a lot of protein, so to rebuild muscles athletes need a lot of protein. Different studies show different recommended amounts, but the minimum would be eating 0.75 gram of protein per kilo and for power sports most experts recommend a lot more then this. So if an athlete wants to repair muscles and replenish glycogen stores they need a lot of protein and a lot of carbs. Of course they need some fat to stay healthy, but they are going to primarily eat high protein, high carb meals. Think chicken breast and pasta (the mainstay of most Premiership footballers diet). To avoid putting on weight they have to maintain a balance between calories eaten and calories burnt (just like the rest of us), so by the time an athlete eats enough protein and enough carbs they don’t leave much room for fat. In other words it’s not that they are avoiding fat, it’s that they are maximising protein and carb intake and fats get sacrificed in the process.
Low fat diets and the general population
For most people low-fat diets are bad news. Low fat nearly always means high sugar/high carb and this has several (all bad) results.
Firstly carbs interfere with the bodies normal ability to regulate food intake. On our own as humans we can’t eat too much fat without feeling sick, or too much lean protein without getting bored. Don’t believe me, try overeating on fat by eating as much butter or dripping (without any bread/carbs) as you can and see how far you get or over eating protein by eating can after can of tinned tuna or chicken breast without any mayonnaise or other sources. Cut out the carbs and it’s hard to overeat.
A standard portion of McDonald’s fries and a large coke has over 1,200 calories. That’s almost three quarters of a grown man’s daily calorie needs. It’s so easy to massively overeat on carb rich foods, but it’s almost impossible to eat too many calories once you take carbs out of the equations. Without any bread, cereal, rice or sugar 2,000 calories a day is a lot of food. Most people won’t get though it all. That’s why the Atkins’ and other low carb diets work.
Even if you do manage to eat too many calories on a high fat diet, you might get fat, but you won’t get diabetes. Diabetes is now the number one killer in the western world and is caused purely by ingesting too much sugar and not burning it off.
If we really want to eat like an athlete, what would our diet be like?
Top athletes match their dietary requirements to their daily activates very carefully. So what would a carefully matched diet look like for a man who works in an office all day, drives too and from work and spends most evenings in front of the T.V.
Lets start with calorie requirements: These are going to be approx 2,000 calories.
Next lets look at carbohydrates: He’s not going to be taking part in any high intensity excise, but under normal circumstances the brain and central nervous system needs around 100 grams of carbs a day to function.
There’s not going to be much muscle breakdown from exercise going on, but there will be some, and the bodies normal hormonal activity needs quite a lot of amino acids (the building blocks of protein). For most sedentary men this would be 50 – 70 grams of protein.
There are aprpox. 4 calories per gram of protein and carbohydrate. So using the above calculations we need around 600 calories from protein and carbs. The rest (roughly) 1,400 calories can be made up of fat. Want to know what this kind of diet looks like? If you were to eat the normal western diet, but took out three-quarters of the bread, potatoes, rice, pasta, sugary drinks and puddings. You would be pretty much there?
So if you want to keep eating like an athlete, you need to start exercising like one.