Metabolic Pathways Graphic

I was lurking on one of my favorite web sites / forums this morning (Calorie Count).  The complexity of the metabolic system was under discussion.  Someone posted a link to an amazing graphic.  I don't understand it really but remain in awe.  Both at our bodies and at the greatness of the artwork, such that it is.  I got it here.

Leptin Resistance

As I mentioned in the last post, I've been reading up on appetite hormones, specifically leptin. 

Leptin is a protein hormone that acts to regulate appetite, metabolism and energy levels.  If leptin is doing its job properly, it signals the brain how much energy your body has and how much is required - in other words, whether you need to eat because you are low on energy or whether you have enough energy and do not need to eat any more.  In the latter case, it should signal satiety.  Because it is manufactured primarily in the fat cells, the amount of leptin in your body is directly related to the amount of body fat you have. 

You would think that would mean that the appetite would decrease, but that is not the case. Unfortunately, for some of us, our bodies have become deaf to the leptin's message that we are full and should stop eating - our cells are unable to accept leptin's satiety messages and we keep eating.  In fact, most obese people have high levels of leptin and have become leptin resistant, in a similar way that some diabetics have become resistant to insulin. 

A WebMD article on appetite hormones levels quotes Louis Aronne, directory of the Comprehensive Weight Control Program at New York-Presbyterian Hospital:  "With leptin resistance, you don't feel full and the more you eat, the hungrier you may get."  Further, the article quotes Scott Kahan, co-director of the George Washington University Weight Management Program:  "The general public tends to think of 'fat' people as lazy and as having no willpower [but] it couldn't be further from the truth...There is no question that certain people are preconditioned to gain weight more easily and more quickly regain weight after dieting."

So, what to do?  It will come as absolutely no surprise that a proper diet and exercise were mentioned again and again as the key.  Almost all of the articles I read also recommended that snacking be limited and that one should eat three well-balanced and nutritiously healthy meals, making sure to get plenty of protein.  I don't know about this part of the recommendation - it is certainly not what I do, even though I am pretty sure that if I am not now still leptin resistant then I certainly was in the past.  I actually eat 6 - 7 times a day consisting of three medium-sized meals and three or four small snacks.  I'm not sure what the rationale is behind the three meals only recommendation, just passing on what I found in my reading.

Some Links:
Alternative Health for Today:  Insulin and Leptin Resistance - Information Worth Knowing
Sharecare: What is Leptin Resistance
Suite101: Overcome Leptin Resistance with Exercise
WebMD: Some Dieters Are Set Up to Regain Weight
Harvard Gazette: Shining Light on Leptin's Role in the Brain
eHow: How to Check Leptin Levels

How Much Did I Actually Eat Before?

I weighed 278 pounds when I made my decision to change – I must have been eating millions of calories a day, right? Out of curiosity I thought I would plug in the numbers to see how many calories it actually was.

Interesting. Turned out to be 2300 calories a day to maintain that weight at my age and height. Guess how much I’m eating now, approximately? About 2000 – 2100. Not that much of a difference really when you look at it from a daily maintenance perspective.

However, I wasn’t exercising at all and I ate a lot of sugary and just generally unhealthy stuff. And even now, if I weren’t exercising a fair amount almost every day both on the treadmill and at the gym lifting weights or going out hiking, my maintenance calories would be just under 1600 per day.

More numbers – how many extra calories did I eat to gain all that weight? I know that somewhere in 1994 or so, I weighed 155 pounds. So I gained 123 pounds in 12 years. Supposedly, you have to eat an extra 3500 calories to gain a pound (and restrict by the same amount to lose one). So I ate 430,500 extra calories to do that, in 4380 days. That’s something slightly more than 98 extra calories a day on average.

To me this just highlights the need to vigilance and care. I already know that I have a propensity for gaining weight, and I have a lot of fat cells that are just waiting for some extra calories to show up so they can grab onto it and store it.

So now, in order to maintain, I know that I must

1. Pay attention to what I eat. This is why, even though it may seem obsessive, I still count and log my calories. It keeps me honest because I love food so much it would be ridiculously easy to start justifying overeating again. And the food I eat is as healthy as I can make it, with only the occasional straying off the path for a gooey treat.
   
2. Get as much exercise I can in a healthy, safe and fun way. I have a desk job where I sit on my butt all day, so I have to stay focused and dedicated to this. If I don’t exercise, I have to restrict my calories down to my estimated maintenance level.
   
3. Weigh myself on a regular basis. Again, I personally consider this a key factor in my own maintenance because it makes it impossible to lie to myself. It’s a number and it keeps things objective.

Metabolism and You: Some Numbers

BMR: something interesting I’ve learned about metabolism while trundling along my weight loss journey. There are various methods of calculating what your metabolism is probably doing if you can’t afford or don’t want to go through lengthy or costly metabolic testing.

Here’s the idea – you want to know approximately how many calories you burn on any given day by taking your BMR (Basal Metabolic Rate) and adding in your typical activity level. Once you have a pretty good idea of that, you can figure out how much of a caloric deficit you want to create by eating somewhat fewer calories than your total burn. A calorie deficit means that you are setting the stage for weight loss. If you don’t want to lose weight, but instead maintain your current weight, you’ll want to eat around the same calories as you burn.

The BMR calculation produces a number that tells you how many calories you would burn if you did nothing but stay in bed and breathe all day – no activity at all, just how many calories you would need to continue existing. There are a number of calculations and online calculators, and I’m sure each has its proponents, but suspect that for most of us they’re going to come up with numbers fairly similar.

You don’t want to eat fewer calories than your BMR because if you deprive yourself below BMR, your metabolism will slow down so that you burn less – a double edged sword for sure. This is where regular exercise – both strength training and cardio – can help, by increasing your BMR. Exercise also just makes you generally more healthy and fit and boosts your ability to burn energy.

Here’s a link for more info about BMR: Wikipedia Link. This BMR calculation uses metric measurements, so if you need them, here are some converters for pounds/kilograms and inches/centimeters: Pounds/Kilograms and Inches/Centimeters

This is the BMR calculation for women that I’ve used to calculate my own BMR, as an example. Figure out and plug in your own numbers to see what you’re burning.

655 + (9.6 x weight in kilograms) + (1.8 x height in centimeters) - (4.7 x age)

655 + (9.6 x 65.77089365) + (1.8 x 166.116) - (4.7 x 51)655 + 631.4005 + 299.0088 - 239.7 = 1345.7093 BMR

This weight in kilograms is 145 Centimeters is converted from 5' 5", age now 51

For men the calculation is somewhat different:
BMR = 66 + (13.7 x weight in kilograms) + (5 x height in centimeters) - (6.8 X age)

If I were male, my calculation would look like:
66+ (13.7 x 65.77089365) + (5 x 166.116) – (6.8 *51)66 + 901.061 + 830.58 – 346.8 = 1450.78 BMR

Using the multipliers for activity level:
1.2 multiplier for sedentary
1.375 multiplier for lightly active (light workout day)
1.55 multiplier for moderately active (probably a typical day for me)
1.725 multiplier for very active (if I really push it)

These are my estimates for burn at different activity levels:
Sedentary burn: 1615
Lightly active: 1850
Moderately active: 2086
Very active: 2321

And if you want to do it the easy way, here’s a link to an online BMR calculator.