Grear video! But does it make sense to use unpaired as opposed to paired? You're looking at difference within the same individuals, so I assume it would be paired (?)
How did you determine that p-value of 0.047 is significant? is there a threshold value that says if its above or below "said number" than that means the diet was effective?
by default everyone assumes that 0.05 is the treshhold value, or in another word more than 95% of the time as long as the value is above 0.05, it will be inside of the data. thus not significantly different, and since the value is 0.047 only it is significantly (different)