Although it accounts for only 2% of your total body weight, the fact  remains that the brain is a food-hungry organ with ten times the  appetite of other organs. In order to function, it uses up a minimum of  20% of your daily calorie in-take. 
In addition to calories, you should also make sure you get good  nutrients for your neurons through a balanced and varied diet. To ensure  your brain gets what it needs there are certain foods you should add to  your diet.
1.  Oily fish (mackerel, sardines salmon) for brain maintenance
More  than 50% of brain mass is made up of lipids, and over 70% of these are  fatty acids that belong to the well-known Omega 3 group. These fats are  crucial to the production and maintenance of brain cells, preserving the  fluidity of cell membrane.
They also play a part in neuron activity. Weakening brain function  and memory trouble can often be traced back to a deficiency in Omega 3
1. Oily fish are one of the best sources of Omega 3, but 
if fish isn't to your taste, consider nut oils and rapeseed oil as equally rich alternatives.
2.  Pulses (lentils, chick-peas) for brain energy
The  brain is said to be glucose-dependent, which means it uses only glucose  to function. It consumes more than 5g an hour, but doesn’t know how to  store it. It therefore has to be regularly supplied your diet via the  circulatory system. It has long been proven that the most difficult task  within intellectual performance, the capacity to memorise, depends on  the level of glucose in the blood
2.
But beware of indulging in sugary foods and confectionery; though  easy to snack on, they can lead to such strong fluctuations that your  system can react violently and reduce blood sugar to below its normal  level. The brain cannot tolerate this and the drop in blood sugar leads  to fatigue and a shorter attention span.
The sugars that are said to be ‘complex’ and which have a low  Glycaemic Index (GI) are therefore crucial. Pulses are rich in these  ‘complex’ sugars, and their GI is one of the lowest. This really works  to allow the regulation of glucose in the blood and its supply to the  brain without creating a reaction of hyperglycaemia. 
If pulses aren’t to your taste either, consider wholegrain foods, especially cooked ‘al dente’.
3. Bananas for a calm brain
Rich  in magnesium, which is essential in the transmission of nervous  impulses, bananas are equally a source of Vitamin B6 (just one banana  holds practically a quarter of the recommended daily amount). This  vitamin is not only involved in the assimilation and use of magnesium in  cells, but also in the metabolism of amino acids and the functioning of  the nervous system through enabling the production of certain  neurotransmitters, notably Serotonin and GABA (
Gamma-
amino butyric acid).
These two molecules seem to create the right state of mind for prudent, calm and measured behaviour. 
If you don’t like bananas, consider prunes or dried fruit instead.
4.  Liver (veal, beef, chicken) for intelligence
The  brain accounts for around 20% of the body’s oxygen needs, and iron is  needed to get oxygen to the brain by means of the blood’s haemoglobin.  Liver is one of your diet’s assets guaranteed to contain this valuable  metal. Equally, liver is one of the most important sources of Vitamin B.  Since the mid 1980s, it has been shown that these vitamins, mainly B9,  B12, B1 and B6, improve cognitive function and the results of  intelligence tests. 
If you don’t like liver, consider ham, beef or nutritional yeast as a
 food supplement.
5.  Red berries for happy brain cells
All  edible berries (blackcurrants, strawberries, raspberries, blueberries,  blackberries etc.) are veritable mines of Vitamin C (blackcurrants have  twice as much concentration in Vitamin C as kiwi fruit, and three times  as much as oranges). They have antioxidant micronutrients that make up  their colour (anthocyanes, polyphenols, flavonoids…)
Together, they not only fight against free radicals which can affect  nerve cells, notably brain cells, but also improve circulation and  strengthen blood capillaries, which enable the best oxygenation of the  brain. 
If you don’t like red berries, then go for kiwi fruit or garlic.
6.  Shellfish for brain function
Though  rich in Vitamin B12 and in protein (notably lysine, a precursor to  dopamine, a powerful neurotransmitter), it is mostly the oligo-elements  in seafood and crustaceans (oysters, clams, shrimp etc.) that are good  for brain function. Oligo-elements are crucial in order to fight and  prevent stress and its inconveniences. Some of these can be described as  ‘therapeutic weapons’ as they have a hand in fighting anxiety, mental  fatigue and nervous disposition.
Manganese, copper, lithium, zinc and iodine have this effect too and can also be found in seafood. 
If you don’t like shellfish, consider eating wholemeal bread, algae (which has iodised salt as in table salt) or wheat germ.
7.  Eggs for brain connectivity
Eggs  contain lecithin and phospholipids, integral to the construction of  brain cell membrane. In terms of feeding intellect, their value lies  mainly in the quality of their proteins. Long used as points of  reference when analysing the quality of other dietary proteins by the UN  Food and Agriculture Organisation (FOA), eggs are actually rich in  amino acids, essential in the production of the principal  neurotransmitters.
This is also the case with acetylcholine, a synthesis made from  methionine and serine used in the process of memorisation, where  noradrenalin (which stimulates learning) and its production rely on the  presence of tyrosine and phenylaline, which are again found in the  proteins in eggs. 
If you don’t like eggs, consider white fish as an alternative.
8.  Spinach for good memory
All  leafy vegetables share a richness in Vitamin B9 (or folates), which is  known to play an active role in the development of a foetus’ nervous  tissue and also in the renewal of blood cells. One of the signs of  Vitamin B9 deficiency is reduced awareness and memory deterioration
3.  This phenomenon, observed in people of advanced age with folate  deficiency, can probably be explained by the fact that Vitamin B9 is  needed for the maintenance of dendrites (arborisation of neurons, where  B9 levels are high).
If you don’t like spinach, go for watercress, lamb’s  lettuce, iceberg lettuce, broccoli or different types of herbs. Of  these, rosemary is worth noting as it has certain flavonoids (notably  apigenin) in its aroma, which possess stimulating properties affecting  concentration and memory through encouraging cerebral blood flow.
9.  Cocoa for brain stimulation
In  Aztec times, cocoa was already considered a medicine. Later, Casanova,  the legendary seducer of 
women, used chocolate as an aphrodisiac with  the kind of effects we know well! Since then, the chemical analysis of  cocoa paste has revealed many surprises; besides the important calorific  benefits, the presence of molecules similar to caffeine (theobromine,  theophylline) and amphetamines (phenylethylamine, tyramine) give  chocolate its true power as a tonic and psycho-stimulant. At the same  time, chocolate’s high magnesium content (330mg per 100g), and the  molecules it contains which are similar to serotonin (the ‘relaxation’  hormone), account for its ‘anti-stress’ and anti-depressant effects.
But that’s not all! Scientists have demonstrated the positive role  flavonoids present in cocoa play in encouraging better dilation of blood  vessels
4. These antioxidant compounds help fight free radicals and guard the brain’s activity. 
Beware of over-indulging,  however. If you don’t like chocolate, drink tea (which also contains  antioxidants) and weak coffee (for its caffeine and its  psycho-stimulating effect
5), but being mindful of excess and without indulging too much at the risk of cancelling out or even reversing the effects.
10. Avocado to keep the brain young
The  avocado is exceptionally rich in Vitamin E. This vitamin constitutes  one of the most powerful antioxidants and protects the fatty tissues of  the brain from ageing. 
If you don’t like avocado, consider oleaginous fruit instead (nuts, particularly hazelnuts etc.).
And don’t forget that, in order to become a real intellectual  athlete, you must equally train your brain with special 
exercises  (
cerebral games, 
memory puzzles…). And you mustn’t neglect rest either  (sleep is crucial for the brain’s regeneration…). In following this  advice, you may not pick up that Nobel Prize, but you will have a brain  that’s at the top of its game nonetheless!
1. Neurology. 2004, 62(2): 275-280
2. Psychopharmacol, 1993, 113: 83-8
3. JAMA, 1983, 249: 2917-21
4. J Hypertens. 2003 Dec; 21(12): 2281-6
5. J Psychopharmacol, 1991, 5: 120-8
             Benefits of a Healthy Diet
It  may sound trite but it's true: If your diet lacks essential nutrients,  it can decrease your ability to concentrate. Eating too much or too  little can also interfere with your ability to focus. A heavy meal may  make you feel lethargic, while too few calories can result in  distracting hunger pangs.
Benefit your brain: Strive for a well-balanced diet full of a wide variety of healthy, wholesome foods.