That is complete BS. What matters the most, are the total calories you take in during the day, and the macros of your meals. This thing of not eating after 6 pm might work only if you eat normally during the rest of the day – this way you end up having 1-2 meals less, and fast for 12 hours approximately, which is intermittent fasting. However, most people will stuff themselves with food before 6 pm, because later they can't eat....