Confused about target weight/body fat %/lean mass

[martinb]

As a Financial Planner, I should be good at maths (!) but I'm having trouble getting my head around what my target body weight and target body fat % means in terms of the muscle I need to build.

I'm 6' tall and currently 212lbs, with a body fat % of 24%. By my calculations, this means I currently have lean body mass of 149lbs.

My target is to get to 185lbs and 10% body fat.

Does this mean that I should a) be aiming to add 17.5lbs of muscle (185 * 0.9 = 166.5 - 149 = 17.5) or adjust my target weight to 166 lbs (149 / 0.9 = 166)?

I'm currently eating 95% Paleo, working out 3-4 times a week on the rowing machine and losing an average of 2lbs a week. My body fat % has fallen from 27% to 24% over the past six weeks as my weight has fallen from 228lbs to 212lbs. Whenever I occasionally lift weights, my weight seems to plateau or go up slightly the next day.

Should I attempt to lose weight down to 166lbs & then build muscle to get me back up to 185lbs by lifting weights, or do something else?

Any advice or tips?

[Waldo]

The # seems high for body fat at that weight/height at first glance. 166 @ 6' is pretty darn skinny. How did you get that #?

You should be lifting weights as you lose weight to try to at least maintain your muscle mass, otherwise you will lose a significant amount of muscle mass along with the fat.

[martinb]

Thanks, Waldo. It could be that my numbers are off - I blame the calculator on my iPhone (and my inability to sense check my maths!)

212lbs @ 24% means lean body weight of 161lbs (212 x 24% = 51lbs, 212 - 51 = 212) so if I want 10% body fat I assume it is 161 / 0.9 = 179lbs.

Actually, that all looks a lot more reasonable now the numbers are right! On that basis, I probably need to add 6lbs of muscle to have a target weight of 185lbs at 10% body fat?

[Corbab]

Your lean body mass is simply everything inside you that isn't fat--muscle, organs, bones, etc. I think that at 6', 166lb is too light. Adding muscle isn't the same as subtracting fat. At 185lb and 10% bf, you'll have 18.5 pounds of fat. If you're looking to build muscles mass, focus more on lifting. Find a good free weight program (like Starting Strength) and follow that, in addition to rowing. You're making good progress, and you should be able to scale up your workout.

My math might be faulty, but this is all you really need to know: lift heavy, eat real food, sprint. You'll see results.

[Gainsdalf the Whey]

Cutting fat while maintaining muscle can be done through lifting weights and eating less calories than your body burns. Or you can just go all Spezzy on it and lift heavy and eat at a lean calorie surplus. She was skinny to begin with though. Check out my sig for more help.

[Waldo]

Thanks, Waldo. It could be that my numbers are off - I blame the calculator on my iPhone (and my inability to sense check my maths!)

212lbs @ 24% means lean body weight of 161lbs (212 x 24% = 51lbs, 212 - 51 = 212) so if I want 10% body fat I assume it is 161 / 0.9 = 179lbs.

Actually, that all looks a lot more reasonable now the numbers are right! On that basis, I probably need to add 6lbs of muscle to have a target weight of 185lbs at 10% body fat?

No, the 24%, where are you getting that number. Most body fat % measurements are very inaccurate.

[aj_rock]

Since you're a financial planner, I assume you're a numbers guy?

If so, listen closely to Waldo. He'll throw numbers at you until they infiltrate your dreams.

Either way, sounds like your primary goal right now is fat loss. At the same time, with a decent program and adequate protein intake, you can totally get thrown off by weight because you put a little muscle on while losing fat. Just keep doing what you do, and when your progress seems to slow down, re-tool at that point.

Don't worry about the BF calculations. If the measurement you're performing keeps going in the right direction, say, belly keeps losing inches, then don't worry about actual BF. Track the measurement.

[martinb]

Thanks, Corbab. I screwed up those original calculations, so 185lbs at 10% is definitely what I'm aiming for. I'm probably getting too hung up over the numbers etc - as you say; lift heavy, eat real food, sprint - see results :-)

[martinb]

Thanks, CoreyD. I guess that whilst I know it's logical that lifting with a calorie deficit will lead to continued weight loss, I've been disappointed to appear to gain pounds on the days following weights sessions. It's one disadvantage of daily weigh-ins, I guess, and I need to get over it as there is nothing to stop me from packing on muscle and losing fat at the same time!

[martinb]

Sorry, see where you're coming from now, Waldo. I've been using my bathroom scales; definitely not the most accurate way to establish body fat % but a good way to measure progress, I hope.

[martinb]

Thanks, aj_rock. Yeah, numbers basically rule my life :-) One of my favourite things about the last six weeks has been my spreadsheet, tracking progress on a daily basis, looking for trends, establishing what works, etc. I'm quite happy at the moment to focus on weight (fat) loss for now, as my body tends to respond pretty quickly to building muscle, based on past experience. What I really need to do is lose the layer(s) of fat that is hiding what is already there! Thanks for your suggestions.

[Gainsdalf the Whey]

Try using a 5 point moving average and focusing on that, not individual data points. It's helped me a lot.

Edit: even better would be a 7 point moving average if you are disciplined enough to weigh in every day. This would negate any weekly weight cycling from eating more on weekends.

[martinb]

Great idea, thanks. I've added a 7 point moving average to my spreadsheet this morning. It now shows weight loss on 43 out of the last 50 days, which is much better than the 32 out of 50 when measured on a single point basis. Much happier now!

[Waldo]

I use a forward/back weighted moving average. I have to modify it at the ends, but overall it gives a great trendline for weight.

The formula I use for it (d5 = day 5, today, d1 = 4 days ago, d9 = 4 days from now)

Avg = (0.2*d1+0.4*d2+0.6*d3+0.8*d4+d5+0.8*d6+0.6*d7+0.4*d8+0.2*d9)/5

At the ends I chop off the days that don't exist and subtract the unused factors from the divisor. It takes a little more work in the spreadsheet, but it is worth it IMHO.

I don't like how a normal moving average is always behind. This formula will keep it behind right now, but within a couple days the trendline will be right, not behind.

[Waldo]

Thanks, CoreyD. I guess that whilst I know it's logical that lifting with a calorie deficit will lead to continued weight loss, I've been disappointed to appear to gain pounds on the days following weights sessions. It's one disadvantage of daily weigh-ins, I guess, and I need to get over it as there is nothing to stop me from packing on muscle and losing fat at the same time!

You aren't actually gaining weight of significance following weight lifting sessions. It is very rare for the body to gain or lose more than 0.25-0.33 lb of fat or muscle in a single day. That is about the maximum that it can synthesize/burn. Everything else is pretty much water. After weightlifting, especially if you don't do it a lot, your muscles will hold a little additional water for a bit. If you do it a lot the extra water just becomes a normal state (if you take creatine supplimentation this effect is further exaggerated, your natural creatine system is what is holding the extra water in yoru muscles). The daily water thoughtput of the human body is >10 lbs which easily hides real tissue weight fluctuations.