It's Great! Oops, No It Isn't: Why Clinical Research Can't Guarantee The Right Medical Answers

"The truth is, few people know the first thing about clinical research. The public reads about a medical research project that announces unbelievable results for a miraculous drug. Some years later, another investigation completely wipes out those initial favorable findings. Hormones Cut Women’s Risk of Heart Disease (San Francisco Chronicle, 1994) Hormones Don’t Protect Women from Heart Disease, Study Says (Washington Post, 2001) The people are confused because we do not understand the process behind these conflicting results. Our health, and in fact, our very lives are dependent on clinical trials, but we know little about them. This book explains the issues the public needs to be aware of when it comes to clinical research. It uncovers the problems in medical investigations that can not be overcome no matter how much care and diligence medical researchers bring to a research project. The basic premise that drives the writing is that it is impossible for medical researchers to guarantee that they can get all the right answers from a single study. No matter how good the investigators are, no matter how well a study is planned, no matter how carefully the plans are executed and no matter how conscientiously the results are analyzed and interpreted – the answer may still be wrong. The deck is stacked against medical researchers and the public – you – should be skeptical of the results no matter how impressive they seem on the surface."

So, is the difference that there isn't much consensus among scientists for nutrition, and if so, why not? It seems to me that a hypothesis like "salt consumption affects blood pressure" should be fairly straightforward to test.

Or is the difference that the public simply isn't aware of what the scientific consensus is regarding issues in nutrition?

So the whole high GI is bad thing taken to the extreme e.g. clean eating, is probably completely blown out of proportion. It's measured in a very isolated ring-fenced setting that most likely doesn't apply to how you eat food anyway. Put bluntly: don't fret too much about eating white rice instead of brown rice (especially if you're counting macros).

http://www.aworkoutroutine.com/brown-rice-vs-white-rice/

That is as inane as disregarding crash test dummy results because they take place in a controlled environment which is not the same as 'real life'.

Or it might not. Testable! Give subjects the same combinations of foods (maybe scaled by body weight) a set time before consuming the test food, and measure blood sugar delta.

In any case, it might be wrong but it's not silly.

http://clinical.diabetesjournals.org/content/29/4/155.full

Talking to them usually results in "more of this and less of that and exercise and being thorough and blah blah blah". That sounds a lot like "I have no real idea of what's going on, but something in this broad spectrum of measures is bound to eventually pay off". That's very different from an answer that one would expect from a true professional, which would be more along the lines of "In this long and complex chain of events, this point here is the one that you need to affect in order to experience the effect you're looking for".

And what goes for nutrition will work for drug interaction monitoring too.

ITYM people's conclusions will slowly adjust to accumulating evidence. The entire process is ultimately steered by experimental evidence.

Errr, I think we know these 'basic' things quite fine. Energy burned needs to be >= energy taken in. It's just complicated for other reasons.

There are a lot of incentives to stay unhealthy. There're the biological incentives (eating a shitload and packing on a few pounds is good if you're in the jungle and might not eat again for a few weeks), and the incredible cultural pressures that prey on those biological incentives (taco bell spends a lot of money to encourage you to make bad health decisions).

Salt, cholesterol, fat, carbs - these are distractions from being healthy. People who eat healthy amounts of reasonable food (although even then, there's that guy who ate twinkies for a year and managed to lose weight by keeping his calories in check) rarely suffer from poor nutrition.

Yeah, everyone knows that guy who was a vegan and ran every day for 40 years and keeled over at 45 from a heart problem. He's the exception.

Two people consuming the same quantity of energy and exerting the same number of joules on exercise equipment do not see identical or even necessarily related physiological effects. There are many, many factors - other nutrients, genetics, timing, the distribution of work over time (short intense exercise vs. long less intense exercise, etc.) and they all matter.

There are skinny people who have never been inside a gym. There are fat people who work harder than you. Obviously you can still influence your outcomes, but "energy out >= energy in" is a gross oversimplification.

Your basal metabolic rate is not much different from the guy next to you of similar age and weight, barring some extremely rare circumstance. I don't know what to tell you, other than that.

> Two people consuming the same quantity of energy and exerting the same number of joules on exercise equipment do not see identical or even necessarily related physiological effects. There are many, many factors - other nutrients, genetics, timing, the distribution of work over time (short intense exercise vs. long less intense exercise, etc.) and they all matter.

Exercise is probably the least important part in proper weight maintenance, because of all the reasons you listed. Most people promoting the 'calories calories calories' mantra will tell you the exact same thing.

Your diet, and specifically how much you're consuming (regardless of carbs/fats/salt/etc.) is critical, the rest is secondary.

> There are skinny people who have never been inside a gym. There are fat people who work harder than you. Obviously you can still influence your outcomes, but "energy out >= energy in" is a gross oversimplification.

Not really. Those skinny people are eating less (in aggregate) than the fat people, again barring some very rare metabolic condition. Guaranteed.

This is clearly some genetic thing - I was the same way; my nieces are the same way (one getting married in a size 2, that had to be taken in). Eats ice cream by the quart, as often as she can get it.

Folks, denial isn't an argument, so please say something instead of just clicking down. I've just mentioned all this not as a straw-man but because a claim of an absolute (Everybody who is skinny isn't eating much) can be disputed by a single counter-example. That's all.

>Not really. Those skinny people are eating less (in aggregate) than the fat people, again barring some very rare metabolic condition. Guaranteed.

Take a look at http://en.wikipedia.org/wiki/Basal_metabolic_rate#Causes_of_... to find actual measured differences. The #1 cause of differences in BMR is lean body mass. A body builder will therefore have a higher BMR than a fat guy of the same height and weight. Energy spent on short intense exercises that bulk you up will have a bigger impact on your weight than long less-intense exercise that doesn't.

It turns out that we can explain about 3/4 of the difference in BMR through known factors such as these. But 1/4 of the normal variation comes from unknown factors, and that variation can easily leave an individual using 10-15% more or less energy than would be otherwise expected. This is a pretty big difference!

Furthermore even if you were right about all of that, you would STILL be wrong! Among the other potential effects of exercise is appetite suppression. So if your goal is to eat less, the easiest route might be 45 minutes per day on a treadmill, and then paying attention to your appetite.

But about BMR: Lean body mass between two people of same height and weight can certainly make a difference, but people tends to overestimate how much of a difference it will make assuming weight stays relatively similar.

(Note that difference in lean body mass certainly can have very substantial effect when you ignore large differences in weight because that opens the door for much larger variations in lean body mass, but note that bronbron was explicitly talking about similar weight)

I'm an amateur power lifter. My lean body mass after abut 10 years of exercise is about 15kg higher than when I was pretty much the same weight but fat. If I'd stated lifting younger (I was about 30) or used steroids, or spent more time with a trainer early on learning the right way to train, I might have added substantially more, but people tend to overestimate how much muscle you can realistically add. My current weight and performance means I'm an advanced lifter, within the top 10% of gym goers easily.

I often see people think they need to add on huge amount of calories when they start exercising, but that's rarely true. My average calorie intake to maintain my weight including what I burn during 3+ intense weight sessions a week, at a weight of 106kg is about 2400. That is not estimated, but measured by tracking weight + intake in detail over periods of weeks. Subtract my exercise and some other activity, and that easily puts an upper bound on my BMR of 2000kcal/day, most likely more like 1800. A lot of kids freak out when they see those numbers, because they've looked at stories about steroid filled freaks of nature that eat 5000kcal+ a day and think you couldn't possibly add muscle at my intake...

Schwarzenegger during his career as a bodybuilder was about my current weight when competing several seasons (he was heavier when he was a power lifter), but he probably had another approx. 15kg of lean body mass where I still have excess fat (if only I could magically transform my stomach fat and shift it to my chest and arms..).

That pretty much bounds the lean body mass difference for someone at around my current weight to around 30kg. I'm sure you could find someone with less lean body mass than I had when I was untrained if you went looking for really sickly people, but I was weak; you couldn't find many with more than Arnold without bumping the body weight up)

It's fairly normal to estimate about 12kcal per kg of extra lean body mass. The difference between untrained me 10 years ago and trained me today then adds up to only about 180kcal. And between untrained me 10 years ago and Arnold, about 360kcal/day.

Of course that's not nothing - 360kcal is a small/medium meal if you're careful. But very few find themselves towards the top of that range, so a difference that large at the same weight is likely not common (I was totally untrained and extremely sedentary when I started training), and if you do, your exercise will tend to dwarf the difference in basal metabolic rate. E.g. one of my workouts burns in the 500kcal range; I end up burning about 200kcal more per day on average. A top level bodybuilder will spend 3-5 times as long in the gym as me every week, maybe more (and on top of that, you are highly unlikely to get remotely close to Arnold level physique without steroids). But note also that this is before secondary effects: When I exercise, I am generally more active outside of the gym because I feel more energetic. I'll be more inclined to walk to/from the train station instead of taking the bus, or take a walk during lunch hour.

You can certainly find "mass monsters" amongst steroid using body builders today that have lean body mass way above that (e.g. Ronnie Coleman), but they are few and far between, and again the amount of exercise you'd put in makes the BMR relatively irrelevant.

if it were a small % of overweight people you might have a point, but the high % of overweight people in US in particular is certainly because of calories consumed >> calories burned.

i think the real tragedy is people looking for magical formulas, or giving up because 'its genetics'. further proof of that is that just about any dieting regiment works, the issue is that most people dont stick to them.

You say that like genetics has nothing to do with whether someone will stick to a diet or not ;)

Kidneys do not turn sugar into fat.

restrict carbs to a minimum and without a diet they will slowly lose the weight

That is a diet. They will lose weight if they consume fewer calories than they spend.

This nonsense is a great example of the awful ideas that people have about dietary science, and how poorly the truth is being communicated.

Make fat feel guilty about their weight and get them to continue eating sugar and corn syrup has only made the epidemic bigger in the last decades.

Controlling what you eat is the definition of implementing a diet, so doing that is not "without a diet".

Neither of which have any direct or consistent correlation to physical activity or food consumed. And that's the problem; everyone's body responds differently to a host of factors, and we don't understand the factors or the responses.

> Neither of which have any direct or consistent correlation to physical activity or food consumed.

is almost always bullshit. People who truthfully track their calories and err on the side of caution (did I eat 1 cup of yogurt or 1.5?) rarely end up surprised.

Sure, some people have thyroid conditions. If you do, you're the minority and you should get it treated. Otherwise, your body is pretty much the same as everyone else's with respect to metabolic rates (when age is factored in).

edit: I shouldn't even say "health" effects; just systemic effects period. Not only is nutrition not exclusively about weight loss, it isn't even about self-improvement. Rather, it's about a basic understanding of the construction and functioning of the human body.

Maintaining a healthy weight is the primary health problem for the vast majority of people concerned about their personal nutrition.

> Because a lot of people are suffering and dying of poor nutrition

In the developed world, they're mostly suffering and dying because of overconsumption (or reasonable consumption of really high-calorie food).

I'm not trying to say that I think it's as simple as 'put down the fork fatty!' or 'put the twinkie down!'.

I'm saying that instead of focusing on 'oh don't eat too many carbs' or 'lower your salt intake' as a silver bullet to 'why is our nutrition shit?', we should maybe be asking those harder questions: why is it so hard to put down the fork? how can we make it easier to be conscious of our caloric consumption?

It absolutely is the primary problem for most people concerned with nutritional issues in developed nations. Obesity (which is quickly becoming the epidemic it's made out to be) carries all sorts of nasty side-effects that are well documented.

Very long term, energy burned will be == energy taken in. If that's consistently out of balance by... say 100 Kcal/day, that's 0.2 lb/week every week or 10 lb/year or 100 lb/decade. How many 50-year-olds do you know who are 300 pounds heavier (or lighter) than they were at 20?

Not really, unless we're counting death. Most people gain weight as they get older.

> If that's consistently out of balance by... say 100 Kcal/day, that's 0.2 lb/week every week or 10 lb/year or 100 lb/decade. How many 50-year-olds do you know who are 300 pounds heavier (or lighter) than they were at 20?

You're phrasing that the wrong way. Your BMR changes depending on your current weight. If you weigh 180 pounds at 20 and you eat 2700 calories a day, eventually you'll reach a point where 2700 calories is what you require to maintain your body weight (probably somewhere in the 220-240 lb range).

To gain 300 pounds over 30 years would require you to constantly be consuming more and more as time goes on.

You're also completely negating the fact that most people would (and probably do) have a 'reality check' once they get into the 200+ range, and reduce their caloric intake (though unfortunately most likely only to resume their high caloric intake once they've dropped in weight a little).

You're agreeing with the post then, that very long term it's pretty even.

Originally I thought the poster meant "it can't be that simple because otherwise everyone would be 500 pounds", but yes, over time it does become true.

http://www.halls.md/chart/men-weight-w.htm

I feel like you're trying to grind some axe relating to weight loss here, but in doing so you are obviously oversimplifying the field of nutrition.

In most developed nations (which, admittedly I assume HN is largely composed of), people have problems with overconsumption as opposed to underconsumption. You're right though, your ideal scenario is energy burned === energy taken in an appropriate weight range for your height and muscular stature.

> Even that basic question is more complicated than you're making it out to be.

It's really, really not.

> I feel like you're trying to grind some axe relating to weight loss here, but in doing so you are obviously oversimplifying the field of nutrition.

I'll repeat what I said in another comment: Maintaining a healthy weight is (or should be, at least) the primary concern of the vast majority of people concerned with their personal nutrition.

I guess that's the equivalent of Stroustrup's "If you understand int and vector you understand C++", for nutritionists.