Whom can you trust?

No, this is not a newsletter about the state of politics in this great country of ours; it would take too long and I do not any answers. Instead, we are dealing with science in fitness and how it relates to gains.

Upfront: in case you haven’t noticed, I love science! Absolutely the best tool to push mankind forward into a future of health and hugeness.
I am also a big fan of Google Scholar but the ability to draw studies with a click of the mouse has its drawbacks.
The big issue is that you can find a study or something resembling a study to support any obscure view point you. 50 bananas a day for fat loss? Why not?

Especially in the fitness world, many coaches and trainees alike start their journey into proving their point from the wrong end. They form an opinion first and then look for studies supporting their belief system while denouncing or omitting everything else.

Naturally, the path should be opposite one: you look at as many studies as possible and try to extrapolate results and from there on form an opinion.

Then you ask yourself: has the study been replicated? How big is the sample? Who is the sponsor? (I came across a study once, touting the benefits of wine that was sponsored by an association of vineyards…)

If you go about it this way phrases like “this proves” or ” we know for certain” will be extremely rare. At the very best, an observational study can find some meaningful correlation. Only experiments conducted in strictly controlled lab conditions can aspire to test cause and effect relationships. 
One issue in the fitness industry is that many studies are done with athletes and even fewer are done in a double blind setting where all variables (e.g., training, diet, drugs) are controlled. The reason being is that its very hard to generate a random, representative sample of people who will willingly go into a weightlifting monastery for 60 days or longer (even though I could think of a few candidates). 
That said, let’s take a look at what we know for sure:
1. In order to lose fat you must create a calorie deficit. That deficit should come from cutting carbs or fat, since protein is critical to keep muscle mass on.
2. If you want to gain muscle mass, you’ll need to be in  caloric surplus, ideally from fat or carbs.
3. To achieve any change in body composition (weight gain or loss), frequency (train every muscle at least twice a week) and progressive overload (increase the exercise weight or lift the same weights more often) are both necessary.
4. For the same purpose, macros and calories matter most; nutrient timing matters somewhat.
5. Most supplements are useless.
As for the rest, such as exercise selection, rep and volume variation, this is where experience and a good coach come in, but if you follow the five points I laid out above you are off to a good start!