What Are The Long Term Metabolic Effects Of Childhood Malnutrition?
Today lets briefly discuss a bleak topic. Childhood malnutrition. Getting adequate, nutritious food to children in developing countries is a known problem, and despite the collective efforts of people around the world upwards of 45% of all deaths in children were still due to the effects of lacking enough good food.  However, not all children that experience malnutrition succumb to it, some survive and not a lot is known about what the long term effects are on their metabolic processes down the line. Especially considering many of the surviving malnourished children go on to eat "normal" diets later in life (ones which are higher in fat and sugars).
The authors of a recent PLoS One article sought to address this, and this article is what we will be discussing today.
It is known that severe malnutrition can lead to issues such as: hepatic steatosis ( this is the accumulation of fat in the liver ) and diabetes (the inability to appropriately regulate blood glucose levels) resulting from improperly functioning pancreatic Beta cells. , 
In this study the authors were looking at mice (yes I know, another mouse model...), the mice were raised malnourished for four weeks (or not) and then provided a high fat/high sugar diet. The sample sizes in this study were quite small (n = 4 or more per group). However that does not mean we can not discuss their data.
To the left we are looking at the average weights from the mice included in the study at the various steps along the way. In the first plot we see the weights of the mice who were on the normal diet, which included protein (NPD), and the malnourished diet which did not include much protein (LPD). We see that the malnourished mice gained a lot less weight during their 4 weeks on the diet. After this the mice were allowed to recover for a while (4 weeks) where the weight gain between the two groups was similar (marked recovery in the plot). Finally the two mouse groupings were then given either normal food (chow) or the high fat high caloric (HFHC) diet. There are two groupings marked in the figure on the far right one with a (#, the normal diet group) and the other with a (§, the malnourished group). We can see that the mice fed the high fat high calorie diet gained more weight then the normal chow mice, but that there was no real difference between the malnourished and non malnourished mice.
Above we are looking at the total body weight of the mice, and we can see that the trend the previous data describes, holds here as well. Despite the initial malnourishment there is no real significant difference the body masses of the two groups of mice by the end of the study. The high fat high calorie fed mouse weight more (purple and green), and the normal chow mice weigh less (blue and red), irrespective of the initial treatment.
In addition to looking at body mass, the authors also examined metabolism through quantifying the amount of respiration (O2 consumption and CO2 production) of the animals. In the plot above "light" refers to the light cycle aka day time when the animals are asleep, and dark refers to the dark cycle aka night time when the animals are up and eating.
The authors observed no difference in the energy expenditure of the mice while they were being fed the normal or malnourished diets, however during the recovery phase some things changed. Above on the left we can see that the mice which were given the low protein malnourished diet had slower metabolic processes then did the mice which were fed the normal diets during their resting time (light cycle). This is carried over to the right, where the mice fed the malnourishing diet (LPD) did not display the increase in metabolism when fed the high fat high calorie diet (HFHC) that the mice who were not malnourished (NPD) display.
The authors also explored glucose sensitivity and found that during the recovery phase after the malnourished diet treatment, the malnourished mice had higher blood glucose levels then the normally fed mice. However this phenomenon corrected itself, and after the 16 week feeding period with the HFHC diet the difference in blood glucose levels between the mouse groupings disappeared. Indicating that the malnourished diet did temporarily result in an intolerance to glucose, but it was not permanent.
One of the other concerns is that a high fat high calorie diet can worsen the issues of fatty liver development that is common (as mentioned above) after people have been malnourished. However much like glucose sensitivity, the authors observed no statistically significant difference between the livers of the two mouse groupings.
Based on the model the authors constructed in the mice they conclude that exposure to a high fat, high calorie diet later in life after having been malnourished in early life does not make one more likely to develop diabetes (glucose sensitivity) or fatty liver disease later on in life. Granted this is only a mouse model, but the lack of observing any difference in this case can only be interpreted as a good thing.
You read this whole article, and in the end got to a non result! Do you feel like your time was wasted? You shouldn't because the positive result would be more unfortunate data and mean increased suffering for those who have already suffered so much due to being born in an area with little food.
Now if only we could get our collective asses in gear and try to help set up appropriate supply chains to better get food to those people who need it the most...