Blood Sugar and Mental Health
Blood sugar is the fuel for the brain and body, so can be thought of a bit like gasoline for a car. A car engine needs the right amount of fuel at the right time. It has injectors and a computer which very carefully monitor the needs of the engine and inject just the right amount - more when accelerating, less when slowing etc. If the injectors are clogged or the computer not working correctly the wrong amount of fuel will go to the engine and it will either get too much or to little fuel to work properly. If the fuel is not clean or the wrong kind, the engine will also not work well.
As with fuel to a car engine,the body and brain also need the right amount of sugar all of the time, and this is regulated by the pancreas, adrenals, and hypothalamus (mainly). However, our modern diet contains huge amounts of pure sugars and processed starches (white flower, white rice, pretty much all baked and processed food products, sugary beverages like pop and energy drinks, natural fruit juices and carrot and beet juice). These foods cause blood sugar to spike - blood sugar levels rise quickly and the pancreas is forced to produce a lot of insulin in order to reduce the sugar load in the blood.
Insulin is a hormone that tells cells in the body to absorb sugar and helps the sugar to be used as fuel or changed to fat. However, when we eat too much sugar and processed carbohydrates the cells can begin to resist the message of the insulin. This is called insulin resistance and can eventually develop into diabetes. Since our nerve cells, and brain, rely on blood sugar for their fuel, this also affects our moods and level of energy.
Initially, eating high sugar foods can cause us to experience more hyperactivity, decreased attention span, higher volatility and/or anxiety or irritability (which is generally quite noticeable in children). Once insulin resistance starts, the sugar and starch is mostly converted to fat and we are likely to feel fatigued after eating high sugar/starch meals and quickly hungry again while also noticing that we are gaining weight.
However, sugar and simple starches are like gasoline on a fire - they burn quickly but not for very long. After the initial flare of energy, the sugar is gone and blood sugar drops quickly. This in turn overtaxes the adrenal glands as they produce cortisol in an effort to maintain blood sugar at the right level. Cortisol has to spike as the blood sugar drops in order to maintain the levels correctly.
Cortisol, however, is also a key stress hormone and it works with every cell in the body to increase their readiness for energy use. Many (probably most) people already have too much cortisol in their systems however, due to everyday stress and the effects of our current culture. In this case, blood sugar spikes add to the already high level of cortisol. The body tries to compensate but it gets harder and harder and the system goes further out of balance.
The brain and neurotransmitters are also affected and this affects mood and thinking ability. Brain and nervous system health is affected and this either exacerbates already existing mental and physical health issues, or increases the risk of developing them. Some mental health issues that can be increased or aided by blood sugar instability are depression, anxiety, ADHD, OCD, and addiction issues.
For all of these reasons, if you want your child's nervous system - or your own - to function well it is helpful to reduce sugar and processed starch intake as much as possible. This means not using pop or soda drinks, fruit juices (especially artificial ones), most baked desserts, almost all breakfast cereals, and almost any food found in a box. This is even more important if your child has (or you have) issues with attention, learning difficulties, mood swings, irritability, anxiety or depression.
Instead of a sugary, starchy breakfast, prepare something with meat or eggs or a good protein. Use whole grains and unprocessed foods so that the starches are more complex and will absorb more slowly into the blood stream.
Lunches and snacks should also focus on proteins or whole foods. Resist the temptation to use pre-packaged snacks as these are almost always high in sugar or processed starch.
Dinners as well should focus on high quality protein, whole grains and vegetables. Lots of advice for this is available on the internet - the paleo diet is one place to start, but there are other systems (such as Eat Right For Your Blood Type) that can also be good.
(Please note that the links I have provided do not constitute endorsements of the websites or the information. They are provided solely as examples to start your investigations).