For several years now, we’ve seen news articles linking Migraine and obesity. The studies upon which those articles were based were inconsistent in population inclusion criteria, gender inclusion, how obesity status is categorized, and other ways. Now, researchers have performed a meta-analysis of 12 studies to “evaluate the association between Migraine and body composition status as estimated on body mass index and WHO physical status categories.” 
This meta-analysis was conducted according to guidelines of Meta-analysis of Observational Studies in Epidemiology.
Peer-reviewed, published research articles found in PubMed, EMBASE, PsycINFO, and CINAHL were searched for relevant studies.
Twelve studies, with data from 288,981 unique participants, were included.
Two independent reviewers extracted relevant data.
Odds ratios (OR) and confidence intervals (CI) were pooled using a random effects model.
Significant values, weighted effect sizes, and tests of homogeneity of variance were calculated.
Risk of Migraine in those with obesity was increased by 27 percent compared with those of normal weight and remained increased after multivariate adjustments.
Risk of Migraine in underweight individuals was marginally increased by 13 percent compared with those of normal weight. When put together with obesity-related risk of Migraine, this supports that both excessive and insufficient adipose tissue (connective tissue in which fat is stored and which has the cells distended by droplets of fat ) is associated with an increased risk of Migraine.
“The current study substantiates that obesity and underweight status are associated with an increased risk of Migraine, and that age and sex are important covariates of this association. These data suggest that clinicians treating Migraine patients should be aware of this association. Further research to better understand the mechanisms underlying this association has the potential to advance our understanding of Migraine and lead to the development of targeted therapeutic strategies based on obesity status.” 1
Lead author B. Lee Peterlin, D.O., commented in an email interview:
“This study substantiates that the risk of Migraine is increased in those who are obese. These findings support that those with Migraine (whether episodic or chronic) should maintain healthy lifestyle choices in order to maintain a normal weight.
Adipose tissue is an endocrine organ, and just like other organs and glands increased or decreased function can lead to health issues. Extremes of body weight [i.e. (obesity (BMI 30+) or underweight (BMI <18.5)] both increase risk of Migraine.” 
Comments and implications for patients:
Given the inconsistencies of previously published studies about Migraine and obesity, this meta-analysis is especially helpful. It pulled together data from 12 studies with inconsistencies in their methods and structure, then reanalyzed the data in a fashion that made the data consistent enough to compare and analyze.
Issues with weight and body composition tend to make us feel defensive, and some people had expressed that they felt reporting on earlier studies was “blaming the patient.” It’s important, however, to realize that numbers and statistics blame nobody. Thus, the results and conclusions of this meta-analysis should be viewed as statistics that verify that obesity and, to a smaller extent, being underweight increase the risk of Migraine.
See more helpful articles:
Cardiovascular Issues Increase Challenges of Migraine Treatment
Migraine Treatments – The Basics of Clinical Studies
Migraine Linked to Higher Perioperative Stroke Risk
 Gelaye B, Sacco S, Brown W, et. al. Body composition status and the risk of migraine. Neurology 2017;88:1–10
 Email Interview with Lee Peterlin, D.O., F.A.H.S. (associate professor in neurology and the director of headache research at Johns Hopkins University School of Medicine in Baltimore) April 7, 2017.
 Merriam-Webster.com definition of adipose tissue.