Discussion

In the contemporary world, intensification of food production and the modification of fats and carbohydrates have allowed growing urban populations in industrialized and industrializing nations to be fed cheaply and generally stably, free of many of the major fluctuations associated with food seasonality. This should be a good thing, except that the consumption of food products developed for mass use has been linked to a number of chronic diseases. Dietary change (as an outcome of modernization and globalization) has led to the emergence of epidemics of obesity, CVD and Type 2 diabetes [11], especially during the twentieth century. 

A subset of epidemiological transition theory [62], nutrition transition theory has been developed by Popkin as an explanatory framework for changes in nutritional health according to stages of dietary consumption types and physical activity patterns, from prehistory to the present. Nutrition transition theory places societal changes towheads industrialized diets and sedentary ways of life centrally to the emergence and propagation of the chronic disease across the world in recent decades.

Table 5. Ages of nutrition transition. (Modified from Popkin 2004. [25])

Pattern

Age

Time

Human Organization

Diet

1

Food collecting

Pre-12.000 years ago

Hunter-gatherer

High in complex carbohydrates and fiber, low in fat.

2

Famine

Around 12.000 years

 ago

Origins of agriculture and animal husbandry

Less qualitatively varied; larger variation in seasonal and periodic availability; periods of acute scarcity

3

Receding famine

XVIII and

XIX centuries

Introduction of agricultural technology, industrial revolution

Increasingly processed; broadly sourced

4

Degenerative diseases

XX century

Urbanization and economic improvement

Major shift to lower nutrient density, higher energy density; excessively high in fat and sugar

5

Behavioural change

XXI century

Postmodern

According to guidelines, to reduce degenerative diseases and prolong health.
Humans are apparently not well adapted for staple foods that were introduced less than 10.000 years ago, including cereal grains, milk, salt, and refined fat and sugar [34]. This type of foods can save lives in the short term but they are directly related with serious age-related Western diseases, single-handedly or in combination [34]. Human physiology seems well designed for a mixture of lean meat, fish, shellfish, insects, and a large variety of plant foods, including carbohydrate-rich fruit and root vegetables. Although some meat/fish/shellfish must be consumed, available evidence suggests that the proportion of meat versus plant food has varied considerably during hominin evolution [52].
 
If there´s one thing really clear is that our ancestors were nomads and they were all the time looking for better places to stay. Their lifestyle is was much more active with a lot of physical activity. Then agriculture and animal husbandry arrived and this led to a more sedentary life, with no need of moving when the resources where low. However, the lifestyle was still active, besides the new improvements they had to work hard both, work and transport. In those conditions it was no necessary the gym, or trying to have 30 minutes per day to go running. After the work, they did already all the exercise needed, even if you were not working in the field, working at home it was also  hard: cleaning the clothes by hand, walking hours to go buying and carry everything back so their expenditure was in balance with their food intake [63].
 

But slowly (or not so slowly) technology put machines everywhere to do everything to make life easier, but less active, less healthy. The modern lifestyle is based on use the time that machines gave to us to enjoy doing things like going in a bar to drink something, sit on the sofa watching the television (while eating something), going to the cinema or theatre... viewed like this is really tempting, but where is the physical activity here? Most of us have jobs that are fully sedentary and after work we continue sitting. The decrease on the physical activity increased all the pathologies like CVD, obesity, diabetes, osteoporosis, cancer, and the level of stress is higher, leading, sometimes, to anxiety.

Nutritionists, medical practitioners, and popular diet authors argue that many of the health problems facing our society relate to discordance between what we eat in the West and what our bodies have evolved to eat. This is, in effect, natural selection at work. Some have argued that a diet more closely resembling that which we evolved to eat will lead to weight loss and better health [64].

As Hippocrates said “Let food be your medicine!”