In Chinese Medicine,there are 5 basic tastes of all the food,which is related to the 5 elements.
In Spring,people may say we should take more food of sour taste.
No.

一.Sweet/Bland is the best taste we should take in Spring.

Reason:

1. Five Elements:

Spring--Liver--Sour--Wood
Four Seasons--Spleen--Sweet--Earth

Spring is the season of sour and it`s strong enough already by itself,if we take more sour food,it will get too much strong and invades the spleen,which we say in Chinese Medicine:The wood interacts or overacts the earth.In clinic,we may see some patients suffering from disharmony of spleen and stomach,diarrhea,hiccup,hyper-acidity.It seems they are diseases and symptoms of digestive system,actually,there must be something wrong with their liver.When liver diseases occurs, it will spread to the spleen, so the Qi of the spleen should be reinforced before it is affected.

2. Spleen itself:

Spleen should be tonifyed in all 4 seasons.And Spring is the season of growing and generating everything.It needs enough energy and the sweet food are the best energy source of Qi and Blood.

二.About the Sweet taste.

Sweet taste is not only the sweet taste,it includes another important taste called Bland.And this one is the one that we should actually take in 4 seasons.

Sweet=Sweet sweet + Bland.

Before saying more about the sweet sweet taste,let`s know more about the bland taste.

1.Bland.

Bland means less taste or no taste,but why it`s included in sweet?
The reason is that most of the bland food,such as rice,noodle/pasta,which are called staple food,could be tasted a little sweet after chewing.During the chewing, the starch in them is turned into polysaccharides.

Unlike that most of the TCM practitioners think,sweet is the taste tonifying the spleen,the bland taste is the one which could tonify spleen and stomach,benefit the middle jiao,and nourish the lung.

Except rice and noodle/pasta,corn,potato,beef,cabbage,fish with scale are bland,too.Chicken are bland,and with a little bit sour.

2.Sweet Sweet.

Everybody knows that it is the monosaccharide making the sweet food taste sweet.
Let`s make it clear, what are the functions of the sweet sweet taste?

1.Detoxify.

In Chinese herbs,there is one famous herb named Gan Cao(Glycyrrhiza uralensis)

Gan Cao
Gan Cao is sweet, and in many formula from Shang Han Lun,you could find it for harmonizing all the herbs` properties.

2.Stop Acute Pain.

It`s effective to drink a cup of sweet water,no matter sugar,brown sugar or rock candy,when you get an acute headache,or cramping,or intestinal spasm due to coldness.

3.Overtake of sweet sweet?

For kids,it`s OK to take some more sweet food than adults because they need the energy to grow but overtaking of sweet sweet will damage their immature spleen.

And for adults,kidney function has started to decrease and spleen has been mature.Too much sweet will be too greasy to spleen and make it deficient.

For diabetes patients,it`s important to know that bland food is necessary for their recovering,not sweet sweet food.

Summary:

Bland food--Staple food--Tonify Spleen-the acquired Qi
Bland food,the energy and nutrition source.

Rice Noodle/Pasta