I don't have any concrete statistics on this but many of us seem to love the taste of food that is unhealthy for us.

Over the centuries, wouldn't it have been a non negligible advantage to those who preferred (and hence ate) healthier food?

So, why don't most of us inherently find healthier food to also be tastier?

Apologies if this is a silly question or something that is frequently asked. I know very little about biology in general.

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    $\begingroup$ I blame cavemen and biochemists.... $\endgroup$ Apr 3 '19 at 18:50

It's a very simple answer. "Unhealthy" foods, for example potato chips, sugary drinks, and other fatty, cheesy or sugary edible items, have only been around a few hundred (at most) years. In prehistoric times (before agriculture, when the primary source of food was hunting and gathering), when food was scarce, fatty and sugary foods would be of great importance. They would supply the body with large quantities of energy (a gramme of fat gives about 9 calories, a gramme of carbs gives around 4 calories). Since we survived mostly on fruits, vegetables, meat, and whatever roots we could find, something as energy rich as, say, a serving of deep fried cheese covered bacon would have sustained us for days. So eating anything with high calorific value, like a fat rich tuber would release 'feel-good' chemicals, like dopamine and serotonin, among others, which make us feel happy (dopamine is also released in response to hugs and accomplishing goals, serotonin is released, in very large quantities, during nicotine consumption).

Our body these days just isn't used to our relatively sedentary lifestyle with guaranteed food. Our body still hoards fat like it did during our time as hunter-gatherers, and our body still secretes dopamine everytime we dig into a sumptuous serving of cake.

A couple of good sources:


Serotonin-releasing brain neurons are unique in that the amount of neurotransmitter they release is normally controlled by food intake: Carbohydrate consumption--acting via insulin secretion and the "plasma tryptophan ratio"--increases serotonin release; protein intake lacks this effect. This ability of neurons to couple neuronal signaling properties to food consumption is a link in the feedback mechanism that normally keeps carbohydrate and protein intakes more or less constant. However, serotonin release is also involved in such functions as sleep onset, pain sensitivity, blood pressure regulation, and control of the mood. Hence many patients learn to overeat carbohydrates (particularly snack foods, like potato chips or pastries, which are rich in carbohydrates and fats) to make themselves feel better. This tendency to use certain foods as though they were drugs is a frequent cause of weight gain, and can also be seen in patients who become fat when exposed to stress, or in women with premenstrual syndrome, or in patients with "winter depression," or in people who are attempting to give up smoking. (Nicotine, like dietary carbohydrates, increases brain serotonin secretion; nicotine withdrawal has the opposite effect.)


Like many pleasurable behaviors—including sex and drug use—eating can trigger the release of dopamine, a feel-good neurotransmitter in the brain. This internal chemical reward, in turn, increases the likelihood that the associated action will eventually become habitual through positive reinforcement conditioning.


There is an intimate relationship between nutritional intake (eating) and serotonin activity. ...

Traditionally, serotonin has been linked to the macronutrient carbohydrate via the intermediary step of plasma amino acid ratios.

TL;DR: You would have starved if you didn't eat fatty foods back before we had food so readily available, so your body automatically stocks up in case you ever run out.

Watch this video for more information: Why our brains love junk food

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    $\begingroup$ You had me at "deep fried cheese covered bacon" $\endgroup$
    – MattDMo
    Apr 24 '16 at 15:02
  • $\begingroup$ @MattDMo deep fried cheese covered bacon is a health food, though - right? $\endgroup$ Apr 24 '16 at 21:29
  • $\begingroup$ theawkwardyeti.com/comic/salad $\endgroup$ Apr 25 '16 at 0:55
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    $\begingroup$ @MalharKhushu It would be great if you can add a citation. Youtube videos are fine as a learning/teaching tool but are not, by themselves, strong references. The video does cite a PNAS paper and some other references. Can you please add those references (and others, like cross references from the paper, if necessary) along with the video link? $\endgroup$
    Apr 25 '16 at 4:21
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    $\begingroup$ Great reply, Malhar Khushu! One additional point... In reference to the cal/g energy densities of fats and carbohydrates, Alcoholism may be positively influenced by the 7cal/g density of ethanol!!! Yay science $\endgroup$
    – Zachariah
    Apr 3 '19 at 18:32

sorry for a not scientific answer, this is general knowledge. you can try to search for proofs you need.

there are several different types of unhealthy food and the resulting addiction/desire to eat them. the unhealthy food tricks the brain.


the brain is built from cholesterol partially.

the brain can make cholesterol from carbohydrates.

so so-called "unhealthy" food it is good for you kind of. unless you are sick.

so some times a moderate amount of cholesterol is good for you in general, the brain can make its own cholesterol. cholesterol supports memory.

cholesterol is bad if you have an internal wound like an inflammation, maybe of blood vessels or heart arteries. cholesterol made by the liver usually patches the would holes. later to be fixed using protein(if there is also vitamin c). however, if there is an inflammation going and there is a wound filled with cholesterol, new cholesterol will stick to already existing cholesterol. and clog arteries worse.

depriving the brain of cholesterol deprives memory. because neurons make vesicles - like small soap bubbles filled with dopamine that marginally pre-excite neurons. those vesicles are made of cholesterol. if you ingest something that dissolves cholesterol for a long time like a statin or antioxidant you will lose memory and lose the ability to form memory.

also, the brain is energy hungry, so it brain gets activated on high energy foods. however, if fructose or sugar is ingested with food. a large percent of it is stored into fat. using insulin that is made from sugar.

chemical foods: like things that make the brain make neurotransmitters like acids, ions, and sweet poisons are bad for you.

they trick the brain and stress the brain. things like coffee and sugar and sodium glutamate. coffee makes adrenaline and ticks you to release saved energy. sugar acts on dopamine center and tricks you think you do something good even if it is bad. sugar also gives you some glucose. however, all dopamine from sugar is consumed immediately.

some other things dopamine-making:

the brain seeks dopamine, and while on dopamine the brain does not think rather acts as before in an automatic manner. like, do the same thing again. also if the situation not as before the brain will mistake. sometimes brain confuses one thing to another. because they both make the same level of result. one real one fake. the fake quicker and you need to do it again and again. so people fall for a quicker and easier way. the solution is to delay time, to prevent instant action and try to solve basic body needs like rest and food


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