Under and over-nutrition

Those are strange terms, aren't they? But if the body isn't getting what it needs, that's what happens—and they are actually two different, opposite forms of malnutrition under-nutrition is a type of malnutrition caused by inadequate food intake or the body's inability to make use of needed nutrients (all the various things our bodies require), while over-nutrition is when excess nutrient and energy intake over time can lead to obesity².

Under-nutrition

Under-nutrition can develop from inadequate intake or the poor use of nutrients.  Nutrient intake can be hindered by lack of availability (you've seen pictures of starving children before, but it also occurs in US, where it's referred to as food insecurity)—this is what we usually think of as malnutrition. But under-nutrition can also be the result of serious illnesses, dieting, or food allergies. Certain medical conditions (some thyroid disorders, burns or other serious injuries) increase nutritional requirements. If these increased needs are not met, under-nutrition will likely result.  The ability of nutrients to be used correctly in our bodies can also be hindered by intestinal disorders (for example, Crohn's disease or celiac disease), that can cause malabsorption.  

Put simply, our bodies are like fancy cars that require premium fuel from the gas station.  The premium, unlike the regular fuel, contains all of the essential macro- and micronutrients that enable our bodies to run smoothly like a fancy car.  When your child's body is in its critical developing years, it is especially important that they not only receive, but also absorb their required amount of nutrients.  If they don't get the necessary carbohydrates, proteins, fats, vitamins and minerals they require, their under-nutrition can cause malfunction of organs and body processes, in the same way low-grade fuel can lessen the performance of a fancy car:  Some signs of "running on low:"

If you or your child's pediatrician notice any of those signs, it is important to evaluate them as soon as possible. A registered dietitian then can educate you on how to appropriately replace any diminished nutrient(s). Since children require varying amounts of nutrients at each stage of life or if they have various medical conditions), it is important to discuss these with your healthcare team so you can ensure your child does not become under-nourished.  

Over-nutrition

The other side of malnutrition is over-nutrition.  Over-nutrition happens when our bodies are getting too much of one or more nutrients. This increases the risk of obesity, high blood pressure, cardiovascular disease and type II diabetes.   

Using the car example, our bodies are like fuel tanks.  If we have a 20-gallon tank, why would we fill it up with 25 gallons?  The excess fuel would spill out into areas we wouldn't want it to and some would be wasted.  In the same way, excess nutrients that cannot be used for our metabolism and growth spill out and are stored in fat cells, like piles of rubbish. These extra fats create more work for the heart and lungs; they can reduce blood flow to vital organs; and they can result in type-II diabetes, because they lead to insulin resistance.

Either way the malnutrition scale is tipped is a hazard to the body and especially to that of a growing child. It is critical to bring your concerns to your child's pediatrician or dietitian so that they can monitor your child's growth along the reference curves to assure he or she is healthy and away from the two nutritional extremes.