Fall digestion that swings from ravenous to uninterested is not random. Ayurveda reads it as vishama agni, an irregular digestive fire tied to the season rather than one meal, and works with it through diet, Virechana and a full consultation.
A panchakarma program is not sized like a package tier. Length changes what preparation, purification and recovery a body can actually move through, and a practitioner reads prakriti, digestion and the season before settling on three, seven or fourteen days.