I decided this year that I’d be fitter than ever, especially when I realised how much ascent the Wales Trail Marathon entails. There’s just no way I was going to complete that without getting down to a healthy weight. So I set myself a goal of losing 10 Kg in the first 2 months followed by 5-10 Kg in the following four.
1 – How much should I lose? The first thing is to know what should be your healthy weight, and set a realistic target. I started off at around 100 Kg. For my BMI to reach a healthy weight, I needed to be below 85 Kg, and while BMI is a rough tool at best, there was no doubt that I needed to lose weight and this at least gave me an initial target. I would revise that as I neared 85 Kg.
If I decided on losing 1.5 Kg weekly, I’d be at my target in the 10 weeks. This is a realistic maximum figure to aim for, with some sources stating that losing more than this can lead to loss of muscle rather than fat. I decided that would be the best case scenario and in order to make it more achievable I targeted a loss of one kilo each week, with anything over this being a bonus.
2 – How would I lose it? There are so many diets around that I decided instead to apply some science and maths to this and break it down to a simple and analytical method that suited my way of thinking. Losing weight in it’s simplest form should be achievable by ensuring you have a calorie deficit over time. Likewise, eat more calories than you burn and you’ll grow fat. So I decided to give this a bash. One word of warning is that with this method you will need to be meticulous and know the calorific value of everything you eat during the day and keep a note of it. If you can’t do that, you’ll probably fail. I kept a spreadsheet, but you could make use of many calorie count apps and websites that are out there.
3 – How much can I eat? For the average male, 2500 calories is what you need to maintain your weight daily. This of course depends on how active that average male is, how old and their basal metabolic rate. One other major factor is weight, so if you are overweight then you’ll need to burn more calories moving about your daily life than a lighter person. You can narrow your calorie requirements down to estimate your basal metabolic rate by entering your age, activity, height and weight into the calculator on this link. I decided to note my activity as sedentary in order to play safe, and then factor the calories burned each day into this.
According to the link above, I need 2485 calories each day in order to exist. I can easily burn over a 1000 calories a day in activity on top of this.
That’s all well and good, so I need to eat less than I burn, but how much? The calorie deficit is key, and in theory it even allows you to estimate your weight loss over the period. Basically, for every 7000 calories that I burn off over those that I need to exist, I should lose one kilo. This is something that’s generally accepted, but is disputed by some. I decided to use it as it was the only figure I had, without worrying too much about the details. It also makes the maths really easy, suspiciously so some might say, as a 1000 calorie daily deficit should see a weight loss of one kilo per week. To lose 1.5 KG weekly, that needs to increase to a 1500 daily deficit, which is certainly realistic. If I burn an extra 800 calories on average each day and keep my diet around 1800 calories, then I could theoretically lose 1.5 Kg a week.
I would need to run an estimated 8km a day or so to burn that 800 calories, or 56km a week. This was 16km more than I was running at the time, so I had to add some light lunchtime walking to my schedule. Aiming to walk four out of five weekdays, at least 3km each time, would see over 200 calories burned off each time. Not to even mention any distances covered on the hill. However, these estimates were the worrying part of the whole plan, as they can be misleading. To counter that, I decided against worrying about it and just seeing how it went for the first month! Neither would I concern myself too much with detailed nutritional content, but would avoid fat and try and increase my intake of fruit and veg. Under no circumstances would I even consider reducing my carbs, other than to reduce the calories.
But, did this calorie deficit diet work? You’ll have to read part 2 to find out.