Crime and sugar

Biochemical theories claim that there is a causal connection between blood sugar levels, anti-social behavior and delinquency. Theories are mostly represented in the field of juvenile delinquency and presume that poor nutrition affects delinquent behavior. Poor nutrition directly affects the learning process. However, the causal connection between delinquency and candies isn't direct. Excessively low levels of blood sugar (hypoglycemia) can cause the development of negative behavior, nervous behavior, mental confusion, physical weakness, delirium and violence. Excessive consumption of alcohol can cause hypoglycemia and increase aggressive behavior.

Cholesterol and crime

Clinical trials made found a relation between low cholesterol and aggressive behavior in animals. The study conducted in Sweden on 79,777 men and women at age (24-70), who had police arrest records for violent crimes, found a strong connection between lowered levels of cholesterol and violent behavior. Measurements of cholesterol levels of violent offenders were compared with measurement records of non-offenders based on gender, age, type of offender (sexual or violent), alcohol consumption and enrollment year.
Low levels of cholesterol are associated with persons who have difficulties with internalization of social norms and have the tendency to be irresponsible. Low cholesterol levels can cause hypoglycemia.

Vitamins and crime

Vitamins and minerals are very important in a regular diet. Disruption of homeostasis can cause difficulties. Theory states that low intake of vitamins, and minerals can cause delinquent behavior.

In theory, the difference between observed objects can be small, very small, big or very big. In our every day life, we see such differences, but in order to become a hypothesis, the difference between observed phenomenons must be statistically significant. Even small difference can be statistically significant. Statistically significant difference means that the difference between observed objects isn't accidental.
In this case, the statistically significant difference between observed phenomenons exists, but the causality mechanism still isn’t clear. Exempli gratia 96% of a smoker dies from lung cancer, but 15% of a non-smoker also dies from lung cancer. In statistics this phenomenon is known as Fisher's third variable. In concordance with Fisher's third variable theory, violent people just might have a more chance to behave aggressively, than non-delinquents, because of  the unknown third factors.

The biochemical and neurological theories of crime researched the influence of neurotransmitters or hormones, processes of  the CNS and ANS on the criminal behavior. These types of theories take into consideration some influences of social factors. However, neurological and biochemical theories still focus on the biological aspect of crime causation. 

 Lombroso's view on crime