Weight Loss is Just Math

One of the most common questions I am asked about either as a Personal Trainer or as a Strength and Conditioning coach is how to lose weight/fat. The most important thing when preparing yourself to lose weight is to find out how many calories you need to consume to maintain your current weight. I would love to provide you with a golden number depending on whether you are a male or female and have you on the way to the body of your dreams, but the truth is that there is a huge difference in the caloric needs of a 6’5” 300 lb male and a 5’ 100 lb female (I know, rocket science). The web has made it easy, you can find your golden number here: http://caloriecontrol.org/healthy-weight-tool-kit/assessment-calculator/. Before you calculate your number, it is very important when using this website or any other that you enter “sedentary” as your activity level (you may be curious, I’ll get into this below). Okay, got your your number, now what?

The general rule among fitness professionals and weight loss specialists is that you should not lose more than 2 lbs per week, I prefer a general rule to not lose more than 1% of your body weight in a given week. Simply put 1 lb of weight = 3500 calories, so if your goal is to max out on 2 lbs per week, you would need to consume 1000 calories fewer than that golden number we found each day of that week.  Let’s use an example to help show this: when I type my information into the fields of the website linked above, I get a maintenance number of about 2500 calories. In order for me to lose 1 lb per week, I would need to consume about 2000 calories per day (500 fewer calories than my golden number per day) or 1500 calories per day (1000 fewer calories per day) to lose 2 lbs per week. You may be thinking, “but Nick, I exercise, won’t that change the amount of calories I should consume?”

Everyone hears on the news that they should do some kind of physical activity every day of the week. With busy schedules and more access to things you can do on your couch, I have found that very few people work out more than 3 times per week, which is not ideal when it comes to weight loss, but not necessary either. Most people reading this are either PIT members or prospective PIT members, so I’ll relate the calorie expenditure portion of this to group exercise classes. It is very difficult to calculate how many calories you burn without pieces of equipment that does it for you, such as the MyZone belts we have here in The PIT.  You can find approximations of calories expended through different modalities of exercise (running, swimming, weight training, etc.) online, but they are probably not the most accurate due to differences of each person’s size and the intensity at which they work. I highly recommend purchasing something that can measure your calorie expenditure or at least trying out our MyZone system and recording the general number of calories you burn during a bout of training. Using myself as an example once again, it is not uncommon for me to burn 1000 calories during an hour of intense exercise. Let’s say that I burn 1000 calories on Monday, 750 calories on Wednesday, and get lazy and burn only 500 calories on Friday during my 3 sessions of training in The PIT, and I want to lose 2 lbs per week at my current maintenance level of 2500 calories. Let’s look at how my caloric needs would play out through a weekly schedule under these conditions:

M      2500 to maintain + 1000 workout – 1000 deficit = 2500 Calories

T      2500 to maintain – 1000 deficit = 1500 Calories

W      2500 to maintain + 750 workout – 1000 deficit = 2250 Calories

Th     2500 to maintain – 1000 deficit = 1500 Calories

F       2500 to maintain + 500 workout – 1000 deficit = 2000 Calories

Sa     2500 to maintain – 1000 deficit = 1500 Calories

Su     2500 to maintain – 1000 deficit = 1500 Calories

Total Calories for the Week: 12,750

You’ll notice in the above example that I essentially ate back whatever I burned during my workout. My golden number is 2500 calories, and on Monday I burned 1000 calories. I simply ate back to 1000 calories for a total of 2500 calories. On days I didn’t work out, I stayed true to the 1500 calories limit and by the end of the week I restricted 7000 calories for a 2 lb weight loss.

Bonus advice: Weekends are the #1 killer to sustained weight loss. People almost forget that a week consists of 7 days, and go on a feeding frenzy over the weekend. Let’s say I never work out but stick to my 1500 calorie restriction religiously Monday-Friday but go over my limit by 1750 calories on both Saturday and Sunday (which is not uncommon). In doing this, my 5 days of hard work to lose 2 lbs would be cut in half because of 2 days of beer and pizza (both admittedly delicious). That week I would only lose 1 lb, and only if I was perfect throughout the week.

So what should you do with this information?

  1. Get your golden maintenance number
  2. Restrict that golden number by at least 250 calories (.5 lb per week) but no more than 1000 calories (2 lbs per week)
  3. On days you work out, eat back the calories you burn
  4. Don’t let 2 days of splurging spoil a week’s worth of hard work

Thanks for reading this and check out my next article on interval training, which would be a great supplement to your 2 or 3 days per week of training in The PIT.


Nick Nundahl C.S.C.S.

Nick Photo PIT

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