Nutrition

Try cutting out red meat (Beef, Pork, Bacon..mammals) from your diet or just replacing red meat with Chicken and Fish. Eat more vegetables and fruits...In 6 weeks a lot or a little can happen depening on what you do and how your body is. If you don't already do it, try taking a multivitamin pill which will help your metabolism. You can do all of this, but without running or swimming or something, it wont make as much of a difference. If you dont know where to run or you want to know how far a run will be, go to mapmyrun.com - it works like google maps except you can draw out a run. Also, try doing some abs workouts...that'll cut some fat off of your midsection.

Hi, This is a great question and I am glad you asked it. First you have to ask yourself how much do you want to lose? People like to make losing weight sound really complicated, but it really boils down to a very simple principle:
to lose weight, calories out needs to be greater than calories in.

There are so many diets, gimmicks or fads out there it blows me away. Yet not one of them empowers you to understand the mechanisms of weight loss (well to be fair I suppose some of them might). And this is truthfully the biggest weight loss secret: empowerment. You may know this already, but let me give you lesson #1, and in my opinion this is the biggest lesson of them all.

One pound of fat = 3500 calories.

So in simplistic terms, that means you would have to create a 3500 calorie deficit to lose one pound of fat (of course its never really that simple, but it almost is :-) ).

Now the next thing I want to tell you may seem to complicate things, but in my opinion, it really doesn't. So lesson #2 is:

Different types of calorie deficit inducing activities may burn different types of energy sources in your body.

So, if you fasted for two days and drank nothing but water (I do NOT recommend this), you may create a 5000 calorie deficit, but guess what? A lot of that would probably come from precious muscle tissues! Your body can use muscle for energy when it is highly stressed. So extreme calorie deficits / diets are not a great way to lose weight, since you can lose a bunch of muscle and not much fat. Also many extreme dieters experience rebound, where they gain a bunch of fat back shortly afterwards, since their body may go into "fat storage mode" since it thinks calories may be dramatically restricted again in the future.

This leads us to the other thing I wanted to mention and that is that certain diets such as atkins, and south beach CAN trick your body into burning more fat than usual (in Atkins case through a process called ketosis). But these are metabolic tricks that are not really recommended for the long term, and are (in my opinion) not very good for you in the first place.

So I guess another lesson I would like to share is this:

Your body burns different ratios of carbohydrates and fat during different activities and activity intensities

So for example, if you are just sitting there watching tv, you might be burning 40 calories, 60 percent of which could come from fat. And if you did some sprinting and interval training for 20 mins, maybe you can burn 250 calories and 40 percent of that could come from fat (100 fat calories burned), and if you went walking for that same 20 minutes, perhaps you can burn 100 calories, 65 percent of that from fat (but then you only burned about 65 fat calories). Many people like to talk about the "fat burning zone" for cardio, and while it may be true that exercising at lower intensities burns a higher percentage of fat, you are burning much less calories since you are burning less calories per minute during the exercise (because of the lower intensity).

Now all of this is great, but how do you determine how many calories you should expend and intake in a day? This leads me two two more things everyone should be aware of:

Most people UNDER estimate how much they eat in a day (more on this later)

and

Know your BMR

Your BMR is your "basal metabolic rate". And this is how many calories you would expend in a day just sitting there not doing much. This helps you determine how much you can eat without gaining or losing weight. Most calculators only give you an estimate though, so it's a good idea to take the number with a grain of salt. And also, if you live an extremely sedentary lifestyle, it is possible that your metabolism is lower than average and your resulting BMR could be lower (although we know is this probably not true in your case). So lets say you are an active person, and have a relatively low bodyfat percentage, and your BMI is roughly 2000 calories per day (this is just an example, I will give you a link to a BMR calculator after this). This means you could eat 2000 calories in a day and not gain or lose any weight. Now, as we discussed before, it is important not to put your body into an extreme calorie restriction, since your body can catabolize your muscle tissue for energy.

So lets say (just for example) that you create a 350 calorie deficit per day through diet and a 350 calorie deficit per day through moderately intense exercise (say 30 mins of elliptical training, 60 mins of cycling, etc). These two things combined would give you an approximate 700 calorie daily deficit that would add up to about 3500 calories in 5 days. Since I recommend a rest day, and you wanted a cheat day (I don't beleive they should be on the same day) you might as well not count the 2 days on the weekend. So to summarize, this would add up to about 1 pound of fat loss (approximately) per week.

So lets summarize an example (remember this is just an example):

BMR = 2000 calories
Deficit = 350 calories from exericse, 350 calories reduced from diet, total 700 calories

Now in this example, the person could eat 1650 calories (350 dietary deficit) and would need to exercise 5 days a week for a duration and intensity long enough to burn 350 calories. Every week (counting 1rest day and 1 cheat day) they could theoretically lose 1 pound.

Ok, now you are probably getting sick of this post, but here is one of the last things I want to share:

Women, because of their lower lean body mass and generally higher bodyfat percentage burn MUCH less calories than the average male

Now, this is very important to know, because it limits how much weight you can lose in a short period of time in a healthy fashion. I tell you this because I hate seing women work so hard and at the end of the week get very frustrated that their husbands may have lost 3lbs and they only lose 1lb. But the fact is, if you were a 350lb male, and you walked for 20 mins around the block every day, you would see the weight just peel off initially, this is because the effort you expend is directly proportional to your body mass. So again, I mention this, because you said you were a 15 year old girl at 5'3 and 150 lbs. Now you won't burn anywhere near as many calories as that 350lb guy, so you will lose much less weight than he does for a given activity.

Now here is another thing I have been leading up to all this time. Many experts suggest that the maximum "healthy" amount of weight a woman should lose in a week is no greater than 2lbs. My personal suggestion places this closer to 1lb. This is because I feel (at your low bodyweight) you will have a tough time meeting your nutritional needs if you try to lose more than that. So first of all, I would suggest going here: http://www.healthyandhot.com/?q=bmrcalc and getting an estimate of your BF% and TDEE , and posting all those numbers here so we can see them. It will help us determine what would be a "healthy" approximate fat loss rate for you. Frankly, I think a healthy goal would be 1lb per week.

One other recommendation I can make (and this is perhaps the most boring thing on the face of the planet) is document everything you eat for a week. As I mentioned above, in my experience, people dramatically underestimate how many calories they eat in a day, and keeping a log for a short period of time may give you some perspective on where the excess calories come from.

Also, since you live in Canada where healthcare is "free" I would recommend a quick trip to the doctor to discuss your plans and make sure there is no prior medical history that would prevent you from embarking on a weightloss plan.

I just wanted to summarize with my own personal experience. At one point in my life I got very fat. I was always a very athletic person, but one time I really let my weight get out of control for various reasons, and when I finally did get back into shape, I really didn't cut calories from food that much. I was able to lose a lot of weight (about 50lbs) in a relatively short period of time because I did low intensity cardio for about 2 hours a day (cycling) and mixed that up with higher intensity interval training a couple days a week, and I tracked my BMR and my calorie expenditure very, very closely. I also napped and slept a lot to recover in between. So in one day, I might get up and go bike for an hour, then have a one hour nap, and then later go run for 45 mins. I didn't really cut very much calories, I just ate very healthy. Using the BMR tools and calorie counters on the cardio equipment at the gym I could very precisely lose exactly a certain amount of weight every week. by just doing the simple math of my calories in vs my calories out and then seeing how much of a deficit I created though exercise.