>>12085403The two main problems with modern processed foods are, (1) lack of fibre and (2) excess of sucrose. By and large the amount of vitamins and minerals in foods are adequate as long as you eat a broad range of foods.
The problem with a lack of fiber is that it exacerbates postprandial hyperinsulinaemia, meaning that any glucose (or protein) load you ingest will be absorbed much more quickly by your intestines which will hit the liver with a higher glucose load. If this effect is combined with the insulin-resistance effect of sucrose (due to the fructose), then this will contribute to the metabolic syndrome seen in the vast majority of the Western population, which then causes diabetes, hypertension, hyperlipidaemia and therefore heart disease, kidney disease, stroke and Alzheimer's disease. The mechanism underlying this is likely to be due to the high glucose load combined with fructose will cause fatty deposition in the liver (so called NAFLD) causing the hyperlipidaemia and hypertension (related to hyperuricaemia and renal dysfunction) and thereafter fatty deposition in the pancreas which will cause the diabetes, completing the metabolic syndrome. Of note is that this effect also causes dysfunction in the feedback signals that are sent to the brain (via leptin, ghrelin) to inhibit the satiety centres of the brain, this is then the cause of obesity.
Another problem is that a lack of fibre means less nutrients will enter the distal small intestine and colon, which means your gut bacteria will not have as much food to eat. This can cause disturbances in the nature of your gut bacteria which may have health consequences down the line, though the exact consequences of this is as of yet unclear. Moreover, a lack of fibre also cause a lack of satiety which attenuates the Western diet's obesogenic effect.
