-disclaimer - this is in no way intended as medical advice.
-caution - fasting may lead to illness/injury, especially if physical activity levels are not adjusted.
The nature of living things is to survive (eat) and reproduce. This goes all the way down to a cellular level. It is at the very core of 'life as we know it'. Consequently, any non-full living being, will respond to finding suitable food, by eating. Unless there is an active signal to the contrary. All this means that there are only 2 ways Fasting can actually happen:
-prevent the finding of suitable food. (Solution - start with zero high-temptation foods in the house, and buy only what you plan to eat that day.)
-provide a signal of sufficient strength and continuity to prevent eating. (The main scope of this article.)
A very clear idea when- and how much you are going to eat, is the absolute minimum requirement. Without it, the mind will constantly look for creative ways to justify eating sooner, rather than later. (Because its in your NATURE, remember?) I can not emphasize enough, how important this is with regard to success in fasting. Without this, a continous signal to not eat, becomes impossible.
Ideas/thoughts come in various forms, but for absolute clarity, nothing beats a picture a.k.a. vision. For me personally, the following type of calendar with a distinct color coding for NO-food-days, has proven to be extremely effective. Its somehow easy to remember a combination of week-day and color. below is an example of a calendar I used in the past, when doing 3 fasting days pr week, and only a single (large) meal on food-days. It creates a strong link between Monday/Thursday/Saturday and the color RED and it being a NO-FOOD-day.
Time for some more cautioning. Doing 4 meals pr week for 10 weeks, is what I consider 'hardcore'. Outside of short walks, I did no exercise during the period, and dropped from 94kg to 79kg. It never felt unhealthy, except lack of physical energy, BUT when I started going to the gym after ending the fasting, I was prone to very bad joint injuries. (the type that is painful and lasts for weeks/months). Consider yourself warned: you need to re-introduce exercise very gradually.
Another thing that helped immensely, was to consume a spoon of dry cocoa powder dissolved in hot water, when the hunger got really bad. Cocoa is rich in minerals, to protect us from going deficient during the fasting period. It also contains certain compounds that have mild toxicity in high doses, leading the body to reduce hunger as a sort of defense mechanism versus eating too much of such foods. Try eating a large serving of dark chocolate, and you will know what I speak of.
-Create a visually strong fasting calendar/plan
-Empty your house of high temptation sweets/foods. Buy Cocoa powder.
-Consider reducing your exercise regime.
Edit - Forgot to mention another thing I do to curb hunger, in addition to the cocoa powder.. When I do eat, I eat mostly meat and cheese - foods that digest slowly while providing a steady stream of energy to the body. (The worst thing you could eat is a very high carb meal, due to blood sugar drop after initial surge, producing very strong hunger.)