It's very easy to observe the changes you mention: A lack of energy in activities in the short term, which you can control with diet adjustments. In the long te

It's very easy to observe the changes you mention: A lack of energy in activities in the short term, which you can control with diet adjustments. In the long term (over the course of a few months), you should be tracking your weight chart and reducing your intake. The body can adjust to caloric deficits, but not so much that consistent effort over weeks will be blocked. I think it's necessary to mention how to deal with these changes, whenever they're mentioned.