<i>if you&#x27;re not losing weight you&#x27;re cheating on your diet or lying about your exercise</i><p>Not necessary lying. But I have read countless stories, where the TLDR; would be &quot;I thought I was eating very little and very healthy but then I bought a kitchen scale and started weighing and logging everything and OMG was I wrong&quot;.<p>I was also sceptical about counting calories and never needed to do that and was at healthy weight. But recently started for some fitness reasons, and here&#x27;s a personal anecdote for fun:<p>Greek salad is a very healthy meal, where olive oil, a very healthy oil, is used as a dressing. So I always just put &quot;some&quot; in it. With a scale, turned out that was 40g. That served 2 people, but still: almost 200 cal from just dressing from just one meal. Another thing I noticed was that olives and feta cheese were under 20% of the salad volume, but over 80% calories. So just by varying the amount of these I could bring the serving calorie content anywhere from ~100 cal (substituting olive oil with balsamic vinegar) to ~500 cal.<p>So I can see how people may honestly say &quot;oh, but I eat nothing but salads and still can&#x27;t lose&quot;.<p><i>why is it impossible to vary with one individual over time, or change drastically in a short period of time?</i><p>Because there is little to no evidence for that, and I&#x27;m talking about metabolic ward quality evidence.<p>Sure, if you&#x27;re in calorie deficit, your metabolism will slow somewhat, but not drastically and not in a short period of time. Sure, some medication plays tricks with hormones that regulate hunger, but not so much with metabolism directly. I don&#x27;t know about conditions where metabolism will drastically slow down in a short period of time. Even under water fasting it takes at least 72 hours of 0 calorie intake to notice a measurable change.