Too less - nutrient deficiences

The contribution of different macronutrients to dietary energy is highly variable across the world: 19% and 35% for protein, 22% and 40% for carbohydrate, and 28% and 58% for fat intake [54]. Carbohydrate from processed grain and sugar-rich products are the main products from the industrialized populations. A person on the average United States diet received around 52% of their dietary energy from carbohydrates, 15% from protein and 33% from fat. Based on a contemporary hunter-gatherer diet, [55] the relative macronutrient composition prior to the origins of agriculture was 41% from carbohydrate, 37% from protein and 22% from fat, approximately. If this study can be extrapolated to our ancestors diet, then carbohydrate consumption has largely displaced protein intake in contemporary industrial diets [34] bringing implications for weight control and health, as diets that are high in protein (not necessarily from animal sources alone) but within safe physiological limits may help weight control [56] and have beneficial effects through increasing satiety and suppressing hunger [57].

Figure 9. Comparision of the Paleolithic diet of 15000 years ago with the American diet and dietary recomentations of the US. From [53].

The shift from diets constituting a broad range on animal and plant foods to ones largely based o processed foods rich in refined grains, sugars, and oils has led to huge decreases in micronutrient intake among contemporary industrialized societies and economically modernizing populations. Comparative data [53] indicate that wild plant foods, both fruits and leaves, often show higher values and more interspecific variation in their content of particular minerals than cultivated ones [58], [59].

Thus, while energy capture is more efficient than ever before, micronutrient capture is failing. Associated deficiency disorders follow where such dietary deficiencies lead. Well in excess of a billion people currently suffer iron deficiency and it attendant anaemia, while iodine deficiency disorders persists, and osteoporosis (associated with imbalanced intakes of calcium, phosphorus and protein) is widespread [60]. Agriculture and animal husbandry probably changed meat consumption patterns and this can be related with a probable decline in iron intake; among present-day populations, iron intake is limited by economic, cultural and ethical restraints on meat consumption [11]. As the physiological demand for dietary iodine has increased with increased carbohydrate intake after adopting agricultural lifestyles and diets, environmental iodine supplies in many parts of the contemporary world have become insufficient to meet the body’s demand for it. The shift from consumption of a varied animal and wild plant food diet to that of a less diverse diet underpinned by cereal grains and dairy products has reduced human calcium intake and shifted the cellular state from alkalosis to acidosis, resulting in bone demineralisation and increased risk of osteoporosis [61]. This might not matter if humans no longer needed strong bones, but out-sourcing physical activity to machines (with industrialized societies have done quite successfully) leads to other health problems such as obesity, Type 2 diabetes and CVD. 

This profound shift in diet has not finished yet. New technologies and the demand to feed people are simulating development of new foods, where they be refined carbohydrates or fats [11].