Unfortunately that is far outside my expertise. The study here used a diet that is supposed to mimick the effects of fasting by having a low calorie/protein diet. In the discussion, they say the effects on a growth factor can be measured in blood plasma after 48 hours of fasting, or 48 hours of this diet.
My layman guess is that the best schedule is probably the one you can adhere to.
If it's a low protein diet, couldn't the lack of certain aminoacids which promotes cell growth (and by that, also cancer growth) also aid slowing cancer?
The explanation in the article is sort of along those lines, if cancer cells' inability to switch to a protective state is due to their faulty programming always keeping them in a growth mode:
"Essentially, fasting causes a switch in healthy cells from a proliferative state towards a maintenance and repair state. Malignant cells, in contrast, seem to be unable to enter this protective state because of oncoprotein activity, and therefore fail to adapt to nutrient scarce conditions. Instead, fasting deprives proliferating cancer cells of nutrients, growth and other factors, which renders them more sensitive to cancer therapy and increases cell death"
Why make people search instead of quoting the relevant section?
"The human fasting mimicking diet (FMD) program is a plant-based diet program designed to attain fasting-like effects while providing micronutrient nourishment (vitamins, minerals, etc.) and minimize the burden of fasting. It comprises proprietary vegetable-based soups, energy bars, energy drinks, chip snacks, chamomile flower tea, and a vegetable supplement formula tablet (Table S4). The human FMD diet consists of a 5 day regimen: day 1 of the diet supplies ∼1,090 kcal (10% protein, 56% fat, 34% carbohydrate), days 2–5 are identical in formulation and provide 725 kcal (9% protein, 44% fat, 47% carbohydrate)."
"Subjects in the FMD cohort consumed the provided experimental diet consisting of 3 cycles of 5 continuous days of FMD followed by 25 days of normal food intake."
My layman guess is that the best schedule is probably the one you can adhere to.