obesity socio-cultural perspective

public health

worldwide, obesity has tripled since 1975

In 2026, more than ____ billion adults, 18 years and older, were overweight. Of
these over ____ million were obese

2 , 650

39% of adults aged 18 years and over were overweight in 2024, and 13% were obese.

overweight and obesity kills more people than underweight

39 million children under the age of 5 were overweight or obese in 2024.

double burden of malnutrition

• many low + middle income countries face so called burden of malnutrition

• problems of infectious diseases and undernutrition, also experiencing risks factors such as obesity and overweight rapidly (non communicable disease)

• common to find undernutrition and obesity co-existing within the same country, community, and household

• Children in LMIC are more vulnerable to inadequate pre-natal, infant, and
  young child nutrition. At the same time, these children are exposed to high-
  fat, high-sugar, high-salt, energy-dense, and micronutrient-poor foods,
  which tend to be lower in cost but also lower in nutrient quality

look at graphs in the slides

patterns

collecting food, famine, receding famine, chronic disease (NCD’s), behavioral change

major cause of obesity pandemic

• preferences for fat and sugar

• higher incomes lead to higher fat and sugar purchases

• lower food prices, especially vegetable oil

• Globalization/centralization of the media to promote certain
  aspects of food culture

• Technological factors that affect work and leisure, productivity
  and effort

• Other changes in household purchasing patterns and time, e.g.
  meals eaten outside of home

T2 diabetes mellitus (T2DM)

• more than tripled from 1900-2019

• obesity and life factors - unhealthy diets, smoking, reduced physical activity, represent the major drivers drivers of disability and mortality attributed to T2DM

Metabolic syndrome

• increase from 28-37% among American adults, 1999-2018

Non-alcoholic fatty liver disease (NAFLD)

• 25 to 28% from 1990 to 2019

• The forecasted prevalence of NAFLD for year 2040 exceeds 50%, with an annual
  increase rate of 2.16% for the period 2020–2040

Type 2 diabetes is a leading comorbidity with obesity.

difficult to control, especially in weaker health systems

key point:

• insulin is a main fat storage regulatory hormone

• type 2 diabetes is a loss of sensitivity to insulin secretions

• impaired ability to clear glucose from blood into muscle

obesity transition (stage 1)

• stage 1

• low obesity prevalence

• women >> men

• adults » children

• high SES » low SES

obesity transition stage 2

increasing obesity prevalence

women >men

adults > children

high ses > low ses

obesity transition 3

• epidemic rise of obesity

women > men

adults > children

low ses > high ses

obesity transition 4

-declining

-obesity prevalence

obesity transition theory

• conceptual model which was proposed to describe the evolving characteristics of obesity epidemiology in different countries depending on the stage of
  their economic progression and development

4 distinct stages

stage 1. populations are largely impovershed and afflicted by political
unrest; the overall obesity rates are low, but the obesity prevalence starts
slowly to rise among wealthy middle-aged subjects, especially women, and is
much higher in adults than children. Many developing countries of South Asia
and sub-Saharan Africa are currently at this stage

stage 2:

As countries become richer, the obesity rates continue to increase: more in adults than in
children, there is a faster transition in women compared to men due to their different
adipose tissue physiology, but men start also to gain weight

At this stage, obesity shows a clear increasing trend in groups of lower SES. Many Latin
American and Middle Eastern countries are currently at this stage.

High-income East Asian countries are also at this stage, but with a lower prevalence of
obesity

stage 3:

• the obesity prevalence gap between men and women becomes narrower, and the
  socioeconomic gradient becomes more pronounced with continuously rising obesity rates predominantly among people of lower income

• At this point, obesity rises
  massively and takes on epidemic
  proportions. In children and
  women of high SES, obesity rates
  remain stable (plateau). Most
  European countries are now at
  this stage

stage 4

Finally, the obesity prevalence starts to decline, usually after a period of
previous stabilization. Of note, no country shows currently decreasing trends
or is projected to reduce its obesity prevalence in the near future across their
entire population

in women who eat a poor diet before conception, late gestation fetus directs more
blood to the liver and lays down more fat

key points:

The nutrition transition disproportionately
affects LMIC facing a dual burden of
undernutrition and obesity.
• Global shift from traditional diets high in fiber
and physical activity to modern diets high in
refined carbohydrates, added sugars, fats,
and ultra-processed foods.
• transition is driven by urbanization,
economic growth, globalization of the
food system, and technological change,
leading to rising obesity and non-
communicable diseases (NCDs).
• Mismatch: When individuals exposed to
undernutrition in utero or early childhood
later experience calorie-dense, sedentary
environments→ mismatch occurs between
biological expectations and actual
conditions.