Sunday, June 17

Short Guide To Weight Loss: Calorie Restriction

The previous post was a more generalised guide to weight loss. If you are relatively slim already, or those tips aren't working then you may need to calorie restrict. Calories are the most commonly used units of energy in relation to humans, joules are the better but less used alternative. Your body needs energy for its physiological functions, not enough energy long term = you die. You get this energy from food and drink. If you eat more calories than your body needs, you store it, primarily as fat. If your body doesn't get enough calories, your body uses its own energy stores (primarily fat). Calorie restricting is simply reducing your calorie intake, below what your body requires. This forces your body to use its fat stores (though there may be some lean mass lost).
For some terminology and referencing points 1 Cal = 1000 cal or 1k cal. 1 cal = 4.2 joules. 1 kcal is the energy required to heat 1 kilogram of water, by 1 degrees Celsius. 100 grams of chicken leg = ~ 240 kcal, 100 grams of broccoli = ~34 kcal, 100 grams of butter = ~717 kcal.

When calorie restricting the first thing to do is work out how many calories you burn in a day, which is commonly referred to as basic metabolic rate (BMR) or total daily energy expentiture (TDEE). TDEE is a more accurate estimate as it takes into account the physical activity you do during the day. There are a variety of ways of working out your BMR or TDEE. You can figure it out manually, using formulas such as in this thread. Alternatively you can use one of the many free applications on the internet, on sites such as FitDay. Its important to note that whatever figure you come up with, is an ESTIMATE only and should be used as such. If you want a more accurate figure then you'll need to go a physiology lab or medical facility.

Once you have your TDEE or BMR your aim is to consume 10 - 20 % less calories than the value. If your TDEE is 3000 kcal, then you want to consume 2400 - 2700 kcal a day.  The beauty of calorie restricting is that you can basically eat anything provided it stays within the calorie goals. Lots of doughnuts? Sure but presumably you want to eat healthily and be full during the day. So how do you figure out what to eat each day? Well this is the harder part. I'd start by figuring out how many calories you are eating each day on your current diet, to give you a reference point. Anything you eat, you need to record. Snickers bar? Record it somewhere, on paper or ipad or internet. Cook a meat stew? Weigh and record each ingredient. If its a processed product, then the packaging will tell you how much calories are in the product. Make sure you pay attention to how many grams you actually ate, and how many calories there are per gram (or 100g). If its unprocessed then you'll need to use a site like FitDay (above) or phone apps like MyFitnessPal to calculate the calories. You need to record EVERYTHING YOU EAT AND DRINK. Even if it's a spoonful of honey, record it. If you do this for a few days, you'll get an idea of how much you are eating and how many calories. Thus you can begin to work at reducing your calories.

Generally I'd suggest you eat more vegetables and fruits, perhaps more protein rich foods (meat, dairy, eggs) and less carbohydrates and fat (but not no fat!). As with any method of losing weight, doing exercise is recommended since it helps preserve lean mass. Keep in mind that the quantity of calories burned during exercise is typically a lot less than people expected. 1 hour of intense exercise may only burn 300 kcals. If you eat just 150 grams of chicken leg, you will have cancelled out the energy burned. Exercise should be a supplement to fat loss, not the main tool. Additionally exercise is great for health and hopefully that aren't so superficial you only care about aesthetics.

Losing 1-2 pounds (or ~0.5-1kg) of weight a week would be a reasonable pace. Keep in mind that weight fluctuations may eclipse your weight loss during that week. So again, track a weekly average by weighing yourself at the same time everyday, or taking progress pictures every week. If after a few weeks you still aren't losing weight then you may want to reduce calories further. But first and foremost make sure your diet is bullet proof. Are you forgetting those 3 bags of jelly tots you are snacking on during the day? Are you over reporting how much exercise you are doing? Are you stuffing your face at dinner, and then not bothering to accurately record how many calories you are eating?

Part 3 will deal with some miscellaneous diets, that can help you lose weight by adhering to particular rules. They all work through calorie restricting though, just not explicitly.