Weight: 224.8 (-6.4)
Fat: 32.6% (-6.7%)
Meals: Not available
Exercise: Cardio (Treadmill 33:00 WL3 - 309 calories, 1.94 miles)
Pictures: Front/Side/Back

This week has been mostly, uh, inspirational posts, so I think it's time to consider some theory and education for today. And since we're coming up on the two week mark and I still have "Not available" listed under Meals, I think it's time to look into changing that.

Before diving too far into meal planning, it's important to consider what your goals are. Weight change or maintenance? Better nutrition? Specific health goals such as lowering your cholesterol? In my case I'm looking at weight change, which means calorie restriction.

In order to restrict my calories though, I need to know my break even point or maintenance calories. That is, the number of calories I need to consume to maintain my weight. Without this knowledge it's difficult to decide how many calories to eat to lose weight. Remember, eating too many calories will cause excess amounts to be converted into fat, and eating too few calories will alter my metabolism, which may slow, stop or reverse any weight loss.

As you may remember from earlier blog posts, the rough equation is:

Weight Change = Calories In - Calories Out

Weight change is pretty obvious, and the general rule of thumb is that it takes 3500 calories to burn a pound of fat. Note however that not all weight loss is necessarily in the form of fat. We'll want to work hard to prevent losing lean body mass by preserving or even gaining muscle. Realistically though, we should try to simply preserve during the weight loss phase of our fitness plan.

Calories in is also pretty simple. The food you eat has set number of calories. I'm not sure what the regulations are regarding food labels, but most non-raw foods you pick up will have calorie information available. Restaurants are starting to publish nutritional information either on their menu, a supplement to the menu or on their website. There are plenty of nutritional and calorie specific websites out there and I may do a blog post about those in the future.

Calories out is the hard part of the equation and the reason so many people have problems with weight loss, in my opinion. Most cardio equipment has some kind of calorie tracking feature, although the accuracy of these devices is questionable at best. There are also plenty of tables or calculators to be found on the web that will help you determine how many calories you burn during a variety of exercises and daily activities. This is the easy part of "Calories out".

The problem is "Calories out" includes several factors, which themselves are often difficult to measure. A small portion (10% or so) of the calories you burn is from a process called thermogenesis, which is a really fancy word that refers to the energy required to digest food. That's right, some of the calories you ingest end up powering the digestion process. In fact there is at least one diet based on the idea of "zero calorie foods", or foods that require as much or more energy to digest than go to powering the rest of your body. The last time I looked into that the math was very questionable, and it's not really an idea we want to play around with anyway. But if you want to add bulk to your meals to reduce hunger and feel full without adding a lot of calories to your diet I suggest you look around for some of these.

A larger but still relatively small portion of your calories are expended via physical activity. This includes everything from showering, walking around the office, vacuuming, doing dishes, playing with the kids to full on cardio and other workouts. These activities generally account for another 20% of the calories you burn daily.

The largest and most significant of these processes however is known as the Basal Metabolic Rate and accounts for about 70% of your calories. This energy is used to power your organs as well as basic cellular processes. If you really want to know the biology behind it, I encourage you to explore the Wikipedia article and do a bit more research. But suffice to say, your heart, lungs, liver, kidneys and brain all require energy to perform their jobs. Interestingly, on a per pound basis, your brain consumes more calories than any other organ. That doesn't mean you can do brain teasers and call it cardio though.

Even more energy is consumed by cells all over your body, including fat cells and muscle cells. Fat cells will generally consume about 2 calories per day per pound. Many sources seem to believe muscles consume a lot more, but the sources citing recent research seem to suggest that muscles burn about 5-6 calories per pound. So the next time someone tells you that you need to work out to build muscle because it will burn calories all day long, remember that every 2.5-3 pounds of fat you lose will offset that pound of muscle you gained. Chances are, your weight loss will outstrip your muscle growth meaning you'll burn fewer calories at rest.

Now there are a lot of factors that affect your basal metabolic rate. Age, height and weight are commonly used to estimate BMR, but genetics, diet, fat percentage, hormones and even temperature play a role as well. I've read a number of sources (especially fat acceptance websites) that question the calorie in, calorie out model that seems to be widely accepted. I suspect that some combination of factors is at work that skews the numbers of some folks who get frustrated. "My math says I should be losing weight but I'm gaining instead." Given how important metabolism is to losing weight, a wide range of numbers and variables will definitely frustrate efforts to lose weight by tracking calories. I don't believe this means that people are meant to be fat or that calories don't matter, although I will recognize that there's a lot of oversimplification and estimations.

Note that according to this page on BMR, restricting your caloric intake too much can actually reduce your BMR by up to 20%, and in severe conditions as much as 30%. In other words if you starve yourself to lose weight faster, you may in fact be limiting how fast you can lose weight. To use an example with numbers, if your BMR is 2500 calories and you starve yourself by consuming only 1000 calories to lose weight faster thinking that this 1500 calorie per day deficit will add up to 3 pounds of weight loss per week. Your metabolism might enter "starvation mode" in order to conserve precious calories. A 20% decline would drop your BMR to 2000, meaning that you will only lose 2 pounds per week instead of 3. A 30% drop would result in a BMR of 1750 calories, or just 1.5 pounds of fat lost per week. Returning to the original 2500 calories would cause weight gain until the BMR returned to normal. This is why severe calorie restriction is a bad idea.

So what is a realistic calorie restriction? Well, there's a wide variety of methods to estimate calorie needs. One method is to multiply your body weight by a number of calories determined by your goal. So weight loss would use a multiple of 12 calories, maintenance 15 calories and weight gain 18 calories. Using those numbers and my current 225 pound weight, I would set my calorie count at 2700 to lose weight, 3375 to maintain my weight or 4050 calories if I wanted to pack on more pounds (hopefully because my body fat percentage is down at 8% and I need more mass to build muscle).

Another rule of thumb is to calculate your metabolic rate and subtract 500 calories, with a floor of 1000 total calories. The American College of Sports Medicine apparently has a recommendation that calorie levels never drop below 1800 calories for men or 1200 calories for women. Obviously to use this method, I need to calculate my metabolic rate.

There is a wide variety of metabolism calculators available on the web to choose from. I particularly like the Calories per Hour website as it explains in great detail how their calculations are made and how you should use them. The formula most sites use to calculate BMR, known as the Harris-Benedict equation was first published in 1919 and may not be entirely accurate.

Additionally BMR is a very specific measurement with a detailed method to gather information. Resting Metabolic Rate, or RMR, is a less widely used/known term that may in fact be more useful for our needs. Again, the Calories per Hour website calculates this number along with your BMR. If you want an explanation as to why it may be more accurate, they have an excellent explanation of all the math. They seem to know more than me though, and cite specific sources for their information, so I'll choose to trust them. If I really wanted to be anal I'd take their advice and calculate my entire day's activities and add that all up.

Using their calculator for RMR, my 5'10" 225 pound, 35 year old male self burns about 1962 calories according to their calculations. As you may remember this number only accounts for about 70% of my metabolic rate, with activity and digestion accounting for the remaining. Typically most sites will use a multiplier based on how active you are to determine your total daily calorie expenditure. In the past, I qualified for a sedentary lifestyle which has a 1.2 multiplier, bumping my energy usage up to 2354 calories. Given that I still spend most of my day sitting at the computer, I can probably just add my cardio workout total to that for my final number (2663), or if I didn't have a calorie count I could change my multiplier.

Light activity, which I would qualify as moving around a bit more, walking from room to room, performing household tasks would increase my multiplier to 1.375 (or 2698 calories, very close to my addition of my daily cardio). This ranges all the way up to 1.9 (3728) "Extremely Active" which I wouldn't use unless I changed careers into heavy construction or lumberjack or professional athlete.

I'm pretty happy with my sedentary + cardio number though, so I estimate that 2663 calories is about what I would need to eat to break even. To lose weight without restricting my intake severely, I could drop down to 2163 and that would net me about a pound of weight loss per week which is about what I'm targeting.

Another option would be to use a percentage. Reducing my calories by about 15-20% should reduce my intake to 2264-2130, which is about on target with the "subtract 500" rule.

Incidentally, I tried out a few other calculators to see what results I would get. Going by the same sites BMR calculator, I'd actually be burning 2855 to break even. WebMD's metabolism calculator says 2666. MSNBC says 3330. And MSN believes I would maintain my weight at 2787. These are all with the lowest activity level plus the 309 calories that I burned during today's workout. Although MSNBC had the niftiest flash widget to calculate this number, I'm not sure their source (Lisa C. Cohn, R.D.) is in line with the others. Throwing away that result (which is fully 475 calories higher than the next), the range is 2663 to 2855, which is pretty reasonable.

So for now, I'll begin with the assumption that my break even point is about 2700 calories and I need to reduce to 2200 calories to support a weight loss of 1 pound per week. Working out more, or more intensely, as well as beginning my strength training should increase that number. But 1 pound a week is healthy and reasonable and seems like a good place to start.