Now, I will take the example of USA, but principle applies to any country.
You probably thought I will tell you to go vegan or go plant walnuts.
No, this doesnt exactly require you to give up on meat or to go planting nut trees.
It is just unhealthy, but reduces food costs significantly.
A simple principle is such that the main role of food is to give you calories.
Thus, food which gives most calories per the price of 1$ is best.
These 3 foods come out on top:
1. Sugar
2. Cooking oil
3. Protein
Sugar and cooking oil give you huge number of calories.
Cooking oil has 8000 calories in 1 liter.
Sugar has over 3000 calories in one kilogram.
Sugar is very cheap, and cooking oil is very cheap too, when it comes to the amount of calories it gives you.
Even if you need 2000 calories a day, just 1 liter of cooking oil has enough calories to fuel you for four days.
Also, just two kilograms of sugar have enough calories to fuel you for 3 days.
Now, I am not suggesting that you drink 300 mililiters of cooking oil a day to get all calories you need for the day from oil.
No.
Oil gives you calories from fat. But you need sugar too.
You need fat, sugar and protein to have complete calories.
So you can get 900 calories from cooking oil (100 mililiters of cooking oil), 900 calories from sugar (250 grams of sugar), and 200 calories from protein (50 grams of protein).
This gives you 2000 calories.
Now, I am not suggesting that you drink cooking oil directly. It is usually used with other food, and you dont use 100 mililiters all at once but in multiple meals throughout day. On its own, cooking oil tastes like crap, even if not harmful.
Now, someone might say "I dont want so much fat or so much sugar".
Let me explain this in a way that you will understand. All calories are either fat, sugar, protein or alcohol.
There are no other types of calories, and its not realistic to think you can get over 200 calories from protein unless you are a serious body builder.
So the remaining 1800 calories you can only get from sugar, fat or alcohol.
Alcohol is both expensive and way more unhealthy way, so you are left with sugar and fat.
Food you eat daily contains either lots of sugar either lots of fat. There is no 3rd option unless you get calories from alcohol.
I simply cut out the middle man, and instead of buying sugar in form of chocolate, simply buy sugar in form of actual sugar itself which is much cheaper.
Instead of buying fat in form of sandwitches, simply buy fat in cheaper form, so buy fat in form of cooking oil.
So since cooking oil is cheapest way to buy fat, and sugar is cheapest way to get sugar, using these two can actually cut down your expenses more than any other food group.
The final calories you want is protein. Now, you dont want too much protein.
Its simply because protein is way too expensive. Like, 200 calories of protein (50 grams of protein) would cost you more than sugar and oil.
However, you can buy protein itself instead of getting it from food and then take how much you think is right for you.
Protein on its own costs less than getting it from meat or other forms.
As for vitamins and calcium and other stuff, you can use supplements combined with some vegetables, fruit, grains but in small amount just to complete the nutrition so nothing is lacking and you are not paying too much for it either.
Also, its really easy to get fat on this diet, so make sure you know how much calories you use per day. Reduce fat, sugar and protein intake as necessary.
900 calories from cooking oil means 1 liter of cooking oil lasts you for about 10 days.
1 kilogram of sugar would last you 3 to 4 days.
Protein depends on how much protein you want, but a protein supplement of 2 kilograms would last you 40 days if you use 50 grams of protein per day.
Thats it for calories, but reduce fat, sugar and protein as you increase fruit, vegetables and grains, since these too contain some calories. Now, if you use multivitamin supplement, it usually has no calories, just vitamins.
And always make sure you are getting all nutrients you need, at least in form of supplements if nothing else.
This diet costs about 50$ to 80$ per month in USA, depending where you live.
Its about the cheapest diet there is for 2000 calories.
Now, if you need less than 2000 calories daily, price goes down even further.
This diet isnt exactly considered healthy, but if you want healthy, you have to pay much more.
