obesity Flashcards
leptin resistance
Identified a destructive mechanism at the molecular
level
* Causes a well-known phenomenon associated with
obesity: leptin resistance.
* They found that mice fed a high-fat diet produce an
enzyme named MMP-2 that clips receptors for the
hormone leptin from the surface of neuronal cells in the
hypothalamus.
* This blocks leptin from binding to its receptors.
* This in turn keeps the neurons from signalling that your
stomach is full and you should stop eating.
Douglas Coleman 1970
- Zane andrews 2018
lifestyle factors to low leptin signalling
consuming a high fat, energy rich diet
- high fat diet induced obesity, increased amount of saturated fatty acids cross the BBB and provoke an inflammatory response in hypothalamic neurons.
Inflammation induces stress in these neurons blunting their response to leptin (known as leptin resistance)
-high leptin is interpreted as low and the brain triggers starvation response
Genetic factors to causes of obesity
Mutations in the leptini gene itself, or in one of the numerous genes downstream that are required for leptin actions
this is rare, more common in the downstream genes, which effects certain pathways irresponsive to leptin
risk factor: maternal obesity/ diet and childhood obesity
high fat diet during pregnancy and lactation. A maternal diet rich in saturated fats can cause inflammation in the infants hypothalamus
- it can also prime the reward pathways in infants influencing their food choice toward energy rich foods
Rivera et al. (2015): This study investigated the impact of maternal obesity and a high-fat diet on offspring’s palatable food intake and dopamine signaling. It found that maternal high-fat consumption primed the offspring’s reward pathways, making them more prone to consume energy-dense foods later in life
Sullivan et al. (2010): This research focused on nonhuman primates and found that a chronic high-fat diet during pregnancy altered food preferences, highlighting the role of maternal diet in priming reward pathways
Kleinridders et al. (2016): This study demonstrated that maternal high-fat diet consumption resulted in hypothalamic inflammation in offspring, which disrupted energy balance regulation, increasing the risk of metabolic disorders such as obesity
The prevalence of obesity
Obesity has become a major global health issue. As of 2024, over 1 billion people worldwide are living with obesity, with nearly 880 million adults and 159 million children and adolescents aged 5-19 affected. This represents a significant increase from past decades, with projections showing that the number of adults with obesity could rise to 1.53 billion by 2035(
World Obesity Day
Currently, about two-thirds of adults globally are either overweight or obese. High-income regions like North America and Europe show particularly high rates, with over 60% of adults affected. Conversely, the prevalence in lower-income regions, such as South Asia and Sub-Saharan Africa, is much lower(
World Obesity
Our World in Data
). However, the trend is shifting, and by 2035, nearly 79% of those living with overweight and obesity are expected to be in low- and middle-income countries(
World Obesity
obesity- demographic it affects
people in Northern/western europe are thinner than eastern and southern
Women more likely to be obese
Fehily 1999- obesity is higher in working class women and lower in vegetarians
Most deprived people are obese
china are not obese
white british and black more liekly to be obese
obesity facts
7% of obese people suffer from binge eating disorder (Wade et al., 2006)
