Scientific Reasoning

matyoung125

I'm starting this post with the intent of discussing the application of scientific reasoning to justify what you eat. I'm not advocating people eat X and not Y I simply wish eat evaluate some of the scientific reasoning used.

1) Eating X is good/bad here’s a link to the study that proves it...

Okay so this study seems sound must be true. Is it? I almost guarantee in studying something as varied and complex as the human diet, plus the major challenge in dietary research that is "is eating X the only explanation for change y" there will be studies out there that tell you the opposite. The best we can surely do is consider all studies, weed out the ones with poor scientific method, then take the consensus of opinion from the rest. Also you read this where? Google Scholar anyone?

2) Science has proved it, it's absolute fact
Newton proved how the mechanics of the universe worked. some of his theories even became law. We are still taught Newtonian Mechanics today at school. NASA use his equations. Einstein's theory of relativity say that he was wrong! Science doesn't have all the answers it's just a best guess given what we know at the moment. Opinions can change.

3) Despite what they say I read this study and I've been eating loads of X for 12 months and have lost weight and I feel great.
Really? Can you guarantee you'll feel like that when you are 60? Did the study you read start 50 years ago and proven that eating X everyday is okay?

4) Correlation vs Causation
In China there is less chance of men developing prostate cancer than in the West (it may be Colon cancer can’t remember but bare with me my point still stands up) . Their diet is higher in starch from rice than in the West. So there is a correlation between eating more starch and the reduced chance of developing prostrate cancer. You can plot this on a (very simple ) graph.



So it’s obvious that eating more starch reduces the risk right? Well no what we have here is correlation and not causation. Is the real reason that they eat less protein and fat because they have more starch? Or maybe another factor; genetics, salt intake, being a communist. who knows? Causation is hard to prove. This relates to posts like i didn’t eat X and then Y happened. This is not proof eating X causes Y to happen.


I'm sure I could waffle on but really this is just something to make you start thinking about scientific methodology and thinking before using to justify what you do. I welcome debate.

Ultimately I can't stress enough the importance of using scientific CONSENSUS (i.e. taking ALL the studies done on a subject and then making a judgement based upon on the results of all) and using a quality source of information. In the UK I'd suggest NHS is a good place to start getting advice by experts using a consensus approach. Sorry in the USA I don't know but there must be some government website right?

Now (with the danger of leaving myself open to attack) here are some of my favourite head shake topics I've read on here.


1) "You shouldn't eat fruit it has sugar in it, you'll get diabetes and die."
Well scientific CONSENSUS says eat fruit it's good for you so I will. People with type 2 diabetes are advised to eat fruits as part of their lifestyle change to combat the disease

2) "I eat a diet high in X and low in Y"
Again consensus says long term this is bad for you. Have you tried eating a balanced diet? Why does the government recommend we eat a balanced diet. Conspiracy?
"But I lost weight doing it and I feel great."
Did you loose weight not eating X or by eating a calorie deficit? How you going to feel in 10 years time?

3) "Saturated fat is good."
Well it may be proven so, but at the moment CONSENSUS says too much saturated fat is bad as it can cause heart disease in the same way trans fats do. That's why the British Heart Foundation/Doctors tell you not to eat too much.

Final note

Ultimately guys/gals you eat what you want, you don't have to listen to me. Mine is just one opinion. If you are doing what your doing and it's working good luck to you. Respect everyone x

Seefylol

The universe and food. My two favourite things.

nomeejerome

Critical thinking is not a strong suit for many people, but there are numerous people on MFP that use that skill. It seems the critical thinkers attempt clarifying many points and those that just want to do whatever they want to do label them as "mean", "rude" or "bully." :frown:

pluckabee

If a consensus has already been reached, it is incredibly difficult for new information that goes against the consensus too be considered and make an impact on changing the current view.

For example, saturated fat and cholesterol. The newer studies which have been really well constructed fail time and time again to prove the current consensus that saturated fat is bad for you. The current consensus is based mostly on epidemiological studies which, as you've already said, cannot completely filter out other factors which may affect results.

Other studies that show high cholesterol is positively associated with heart disease and others show saturated fat increases cholesterol but new studies haven't been able to directly prove either that reducing cholesterol prevents heart diseases or that increased saturated fat causes it.

ngyoung

A good number of food studies base their information off of food surveys, asking participants to recount what they ate for a given amount of time. Without your food log how many of you can accurately recall what you ate in the past year? Now tell me if you think a scientific study based on your answer would be good for dictating policy.

The food pyramid and other AHA dietary guidelines originated from many poorly run studies. The leaflet that you can get from the american diabetes association advises
*limit sugar and carbs
*eat a diet of whole grains (wtf?)

matyoung125

pluckabee you make some excellent point and I guess it highlights some of the inherent problems of relying on scientific consensus and the problems faced of epidemiology.
Lets hope to use a well worn phrase, "by standing on the shoulders of giants" today's researchers can come up with a deeper understanding of the effects of saturated fats et al. Good science can't be ignored and if enough evidence points towards something I have faith in the scientific community to change those well established concensuses.

Right now I'm still going to eat saturated fats in moderation!

pluckabee

Thanks mat

I do agree that eventually good science is going to win out and we are going to slowly change the idea that saturated fat is going to kill you, but I do think it's going to be a slow change for science and an even slower change for government bodies and groups such as the AHA who have have a lot of stake in the current consensus.

So, as an individual, I can choose to follow the science now rather than wait for these huge bloated organisations to tell me what to do.

Of course there are risks in that I'm not trained in reviewing scientific studies and the people I trust to review these studies may not be either but I have done enough of my own research and seen enough from others to conclude that I'm probably going to be ok eating a bit more saturated fat than what has been previously suggested.

matyoung125

*limit sugar and carbs
*eat a diet of whole grains (wtf?)

At first look that seems contradictory but I guess by eating wholegrains you'll feel fuller this limit the number of carbs you eat. Also grains like quinoa are lower in carbs can replace rice.

In the UK the diabetes website tells you to eat more starchy carbohydrate foods??. It also tells you to avoid foods high in sugar such as soda but that's due to an increased risk of obesity, a risk factor in diabetes, not the sugar itself. It also says recent studies may show a direct link soda high in sugar and diabetes. Who knows?