Any views on this debate: metabolism, muscle loss, thermic effect of food?

999tigger

Hi would welcome views on how to deal with this. I am having a debate on another forum and I have explained the straight MFP was about a defict being key to weight loss. I have also explained the role of nutrition and that exercise is for fitness. I have also explained that resistance training helps retain muscle by lowering the rate of muscle loss. Textbook MFP.

I have humoured this person, but getting bored now. I dont like to leave issues undiscussed. I dont think she understands the basics about a calorie deficit.

1. My answer to the first bit is it is inevitable to lose muscle as you lose weight, but resistance will minimise it.
2. The second bit seems to argue you cnat eat less becayse you slow a metabolic rate and its makes no sense to exercise and ry to increase it?
3. The next bit mentions a lowering of calories by 50% but such a drastic cut was not mentioned,
4. Mention of losing tissue is just as good as far, thats untrue and na invention by the other person, so ignore that.
5. She then suggests you need to eat enough so you dont lose lean tissue, which in one sense is true as not being over aggressive, but another you cant help losing some muscle whilst at deficit, just minimise it.


Anyway comments welcome.

When cutting calories you are going to sacrifice two important things: Muscle mass and metabolic rate. Your metabolic rate slows down because you eat less, and your resting metabolic rate slows down because you have less muscle mass. Got it? Ok. Now Thermic Effect of Food (TEF) is the technical term for the process which burns around 10% of the calories you intake during digestion. TEF is about 10% of your metabolic rate giving that you are on a diet that is described as an ‘energy balance’ (It means you are eating the amount of calories you are burning off, not too many nor too few). The ‘energy balance’ also means that you are not losing or gaining weight. However, if you are on a calorie deficit diet TEF decreases. Let’s say your ‘energy balance’ is at 2,500 calories a day, which means your TEF burns 250 calories a day. If you drop down by 500 calories, your TEF will also drop by 10% = 50 calories, equalling to 200 calories. Now this study (http://www.ncbi.nlm.nih.gov/pubmed/17095635) shows that subjects were put on a strict calorie deficit diet for a year. Yes,they lost 18 pounds on average, equalling to roughly 10% of their body weight. But they lost 3.5% of their total lean body mass (this includes muscle, bone,and everything else that is not fat). What the study also showed is that they lost around 7% (!) of the muscle in their thighs… So sacrificing 3.5% of their working mass lead to – obviously- decreased strength and aerobic capacity. Now there are examples of two studies (http://www.ncbi.nlm.nih.gov/pubmed/12055316) and (http://www.ncbi.nlm.nih.gov/pubmed/12752838) which show strong connections between aerobic capacity / strength and longevity. A chronic low calorie diet is not doing you any good. So eat less and exercise more is not as good as advertised,mainly because eating less decreases your metabolic rate while exercising more increases your metabolic rate. So…? You are slowing down your metabolism while you are speeding it up? Does that make sense to you? “If a financial advisor told you to run up your credit while putting away money in savings account,would you take that advice?” It is illogical.
This (http://www.ncbi.nlm.nih.gov/pubmed/2352481)study showed that women who cut their calorie intake by 50% lost about 10 pounds of lean tissue (great), slowed their metabolic system by 9% which also caused their exercise to be 16% less efficient. What is bothering that you keep referring to weight loss. As if losing lean tissue is just as good as losing fat. Um, I don’t think so.You need to eat enough calories so that your body doesn’t lose lean tissue! The hormones and chemicals that help you control weight are disrupted when your calorie intake is on a deficit (By the way, deficit does not mean reducing what you eat now. Calorie deficit is when you calculate how many calories you burn every day, and then subtract an amount from that so that your body can eat away on your ‘fat’ to fuel itself. But as I said above, you will start eating away at your lean mass too). A number of studies (https://www.ohio.edu/biosci/profiles/loucks.html) show that lack of calories combined with serious exercise lowers estrogen levels in women, mostly causing amenorrhea. Other hormones (also in men) that could be affected are Leptin, Thyroidand Cortisol. Balanced Hormones mean so much to our health and there is no reason to be messing with them? �"�6�