Internalized Weight Bias – The Science

Primarily genetic

Here, a systematic review that identified 88 independent estimates of BMI heritability from twin studies (total 140,525 twins) found BMI heritability estimates from twin studies =0.75 (75%). Here, Claude Boucher describes that “There is a genetic component to human obesity that accounts for about 60%- 80% of the variability of weight in the population of individuals with obesity and severe obesity.” Notably he describes “Heritability varies across classes of BMI”


Brain centered

Here, in this review paper, Giles Yeo describes that “Genes that are either enriched or exclusively expressed within the brain and CNS have a central role in obesity.” and that the “central nervous system (CNS) and neuronal pathways that control the hedonic aspects of food intake (gatekeeper) have emerged as the major drivers of body weight for both monogenic and polygenic obesity.”.


Here, Alain Dagher looked at Functional MRI in individuals who undertook a weight-loss regimen. He found a “Neural Signature” the best predictor of success was activation in prefrontal cortex (sleepy executive) during the regime and changes were associated with food cue reactivity in reward-related brain regions. (GoGetter)


Strongly influenced by the environment

Here, Hans Rudy Berthoud describes the prevailing understanding of the obesity epidemic to be the result of a collision between this Genetically determined CNS appetite system and the Obesogenic Food Environment which is characterized by Ultra processed foods, Ultra concentrations of sugar, fat and salt, Ultra portioning, Ultra availability and “Health washed” neurologically based marketing.



Here, John Speakman reviews the concepts of set point, settling point and a persuasive theory called the dual invention model to explain how body weight loss is variably defended against and weight gain is variably defended against. Here, Kent Berridge describes the progressive conditioned incentive sensitization model that results in excessive “wanting “to eat.


Not your Fault

The preceding evidence is antithetical to the idea that obesity is a consequence of a lack of willpower or motivation, or someones fault. Here, Rebecca Pearl describes the significant negative consequences of internalized weight bias, the patient belief that weight struggles are “my fault”.


Behavioural therapy

Here, Evan Foreman and Meghan Butryn demonstrate a most effective behavioural weight loss intervention based on adding the following 3 principles to the already established – standard behavioural therapy exemplified by the diabetes prevention program and the lookAhead trial. The three additional principles are 1) a focus on wanting 2) a focus on values and 3) a focus on mindful awareness of thinking in moments of food decisions.



For a detailed review of effective and safe pharmacotherapy please reference the 

The Why, Who, What, When, How and Where of Anti-Obesity Medications Module.

Practitioner Module Videos Are Now Available