As I’ve mentioned before, I tend to find one philosophy within a particular discipline…in this case weight management…and follow that one. For me ‘counting calories’ works. I don’t do that year round…I eat pretty healthy, and my weight has stayed the same, or trickled down over the past 5 years….but definitely in the off-season when exercise calorie burn is reduced, and definately this year, when I’m thinking about building in a specific lower weight goal for the coming season.
So just how accurate are calorie calculations?…not very accurate really…but close enough…sometimes a bit maddening when you realize that losing or gaining weight can be a matter of a few 100 calories one way or the other.
When it comes to food calories, you can be pretty accurate for foods that are in the database of a Food Diary…when a specific food isn’t in the database you have to take a best guess as to the closest thing…even with that though, there are a few things that throw off the results:
- the portion size…is that piece of chicken 3 ounces or 4, or 5?…you really have to weigh it to know…and I do…at least during this off-season period
- in a restaurant, its poor form to bring your food scale out, and take apart the entrée, and weigh each piece, so it’s a moon-shot estimate
- not entering all your food…a few crackers mid afternoon can slip in, if you’re not in front of a computer to enter everything as you go…it’s pretty easy to miss little stuff
However, saying that, just the fact that I’m logging what I eat, makes me much more aware of the calorie impact, and if gravy is on the plate of a restaurant meal, I do think about the ‘calories’ and don’t need the actual Food Diary entry to tell me that I should avoid it.
In fact, before I go to a restaurant for dinner, I’ll update my Food Diary, and see how many calories I have left in the budget for the day, and to a large degree decide in advance what I’m going to eat…I have the mobile app version on my SmartPhone where I can check food calories while I’m sitting at the restaurant…probably not a great thing to do on a first date…might be a bit scary…but I will from time to time pull it out (can you say bathroom break) to check something if I’m really curious for a particular reason. I should also mention that the app allows me to actually enter stuff on the phone…I rarely do that since I ‘am’ in front of a computer most of the day.
Exercise calories burned is a lot less exact. Different charts and formulas will give you very different results…again particularly when you consider we’re talking about a few 100 calories one way or the other in any one day.
Cycling calories burned in particular is all over the place…’experts’ can be _very_ different in their estimate for a particular workout. Respected cycling coach Chris Carmichael puts the bike calorie burn at 8-10-12 calories per minute up to 16 calories per minute if you’re pushing it…and his estimates are a lot lower than many others…depends a lot on intensity…you can see the challenge…speed or power isn’t really enough…there are a lot of variables on the bike. One of many Carmichael articles
Here’s an example: if I enter 1 hour of cycling into My Food Diary in their 16-19 MPH category (first of all, that’s a pretty wide zone of speed intensity) which for me is a standard training pace zone…I’m usually between 17-19MPH on solo rides if I’m not hitting it too hard…it calculates that I burned 1,175 calories for the hour…using Chris Carmichael’s thumbnail formula, it would be 12 calories per minute at 19MPH, or closer to 8-10, at 16 MPH, so 720-600-480 calories for the hour…another variation is that he doesn’t account for weight in the article, although his primary point was about calorie burn and interval training…and used to dealing with guys tinier than I am…but enough to illustrate that it’s an inexact science, with a fairly significant variation sometimes.
So, for me, since I’ve decided on the My Food Diary platform, whatever it comes up with for food or exercise calories, is what I use, rather than trying to constantly massage the numbers one way or the other, and figure that it will more or less average itself out over time.
To stay to the conservative side, I leave in a mattress of a couple of hundred calories to account for variations…that is to say, when I’m focused on weight management, I want my calories ‘in’ to be 200 calories less than my calories ‘out’, or if I want to run a 250 calorie deficit per day (1/2 pound per week), I target for a ‘450’ recorded deficit on a particular day….and on cycling days, even more.