Are obese people addicted to food? Researchers from Harvard University, Children’s Hospital Boston, and Women’s Hospital, all in Boston, Massachusetts; University of Michigan, Ann Arbor; Arizona State University in Tempe; and Yale University in New Haven, Connecticut, used a novel measurement scale to uncover more information about the relationship between addiction to food and obesity.
The researchers analyzed data from participants in the Nurses’ Health Study (NHS) and Nurses’ Health Study II (NHS II) who had answered questions about food addiction. In 2012, the Yale Food Addiction Scale (YFAS) and a modified version of it (mYFAS) were also administered to a random sample of 2,061 women who participated in NHS II. The YFAS has 25 items; diagnosis is based on the patient having ≥ 3 of 7 addiction symptoms in addition to significant impairment or distress. The researchers developed the mYFAS for use in large epidemiologic cohorts by adapting the validated YFAS to 9 core questions with 1 from each symptom group that comprised the 7 diagnostic criteria. The survey also had 2 individual items that assessed for clinically significant impairment and distress.
Of the 134,175 women surveyed, 7,839 met the criteria for food addiction. In the older NHS cohort (aged 62-88 years), the prevalence of food addiction was 2.7%. In the younger NHS II cohort (aged 45-64 years), the prevalence was 8.4%. Prevalence was most strongly associated with age and body mass index (BMI), ranging from 0.3% in women aged 70 to 74 years with a BMI of 18.5 to 23.0 to a maximum of 25.5% in wo-men aged 45 to 49 years with BMI of ≥ 35.0. Women with a BMI between 23.0 and 24.9 were about twice as likely as women with a BMI between 18.5 and 22.9 to report food addiction.
Former smoking was positively associated with food addiction, whereas current smoking was inversely associated with it. The researchers say food addiction may substitute for or replace nicotine addiction. Women who reported depression had about 3 times the prevalence of food addiction. The researchers also cite evidence of an association between a history of child abuse and subsequent food addiction. In the older women of the NHS, living alone was positively associated with food addiction.
The researchers say neuroimaging studies have identified similarities between obesity and drug addiction. Both are associated with reduced dopamine receptor D2 availability, hyperresponsivity in the mesolimbic dopaminergic system, and reduced activity in the caudate during consumption. Moreover, substance dependence and food addiction have both been related to continued use despite negative consequences, difficulty reducing consumption, and high rates of relapse.
The researchers say the association with BMI increased “substantially” through the range of overweight and obesity, but because it was a cross-sectional analysis, they couldn’t determine the cause. Whether food addiction is a contributing cause of obesity, or a result of excess weight, either cause or effect has important clinical implications in prevention and treatment.
Source
Flint AJ, Gearhardt AN, Corbin WR, Brownell KD, Field AE, Rimm EB. Am J Clin Nutr. 2014;99(3):578-586.
doi: 10.3945/ajcn.113.068965.