How do these skill stats work?

[HappyHam]

In all the time I've played this game, I still don't know how skill statistics work.
First of all, when you eat certain food, you gain buffs and bonuses. But what do they do? If I have +2 farming, does it increase the quality of harvests? I've tried and haven't seen a difference.
Second of all, with skill level, what does it mean when I gain 'proficiency'?
With things like axes and pickaxes the number of hits it takes to down certain types of obstacles depends on how many times it's been upgraded, so what could this 'proficiency' stat do?

None of it makes sense to me and I couldn't find info on the wiki. Can anybody explain all of these?
Thanks.

[illumisphaero]

Profiency slightly decreases the amount of energy it takes to use a tool. It also increases the chance for getting higher quality items. For fishing, profiency increases the length of the fishing bar.

[Zero Angel (Ocelot)]

Normally, each tool costs 4 points of energy to use. Each level gained increases the related tools' proficiency by 1. Each point of proficiency reduces the energy cost of the tool by 0.1.

Levels do seem to influence harvest/gather/fishing qualities, however a +2 isn't a major difference, you'd have to do a scientific test with a lot of samples in order to determine whether it makes a difference or not, as well as whether Level 10 is the upper cap on a skill or if it can go past Level 10 with foods and such.

[HappyHam]

Ok. Thanks everyone.