Key points
- Stress reduces sleep duration and quality
- Stress-driven sleep impairment worsens diet quality and encourages fat gain
- Stress also increases inflammation and fat storage independently
- Stress-eating results in greater food intake and reduced food quality
Reviews of the evidence show a strong bi-direction relationship between stress and sleep, food intake. In other words, factors like stress worsen sleep and increase food intake, resulting in weight gain, and conversely, worsened sleep drives poorer food choices, and poor food choices worsen sleep, and obesity is a known risk for sleep disorders.1
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Chronic stress promotes a shift to over-eating. This is in contrast to acute stress which typically reduces food intake due to the effect of the catecholamine stress hormones that act as both stimulants and appetite-suppressants. Hyperactivation of stress responses also promotes metabolic shifts that encourage fat-gain along with an increase in inflammation which in turn is associated with increasing fat-gain. Also, detrimental changes occur in the microbiota of the gut and this could also encourage a trend towards adiposity.2
Chronic stress promotes a shift to over-eating. This is in contrast to acute stress which typically reduces food intake
Research has demonstrated:
- In a study of 277 male workers, a strong association was found (even after adjustment for confounding influences such as age, gender, and calorie intake) between the amount of job stress and weight gain.3
- A 20-year study of 3872 men and women in Sweden found that stress from high job demands predicted ~30% increase in weight gain.4
- A significant relationship between work-related stress and weight gain has also been seen in a Norwegian cohort.5
- Parents of cancer patients are more likely to gain weight than parents of healthy children and the magnitude of weight gain is related to the degree of psychological distress that the parents experienced. Parents of cancer patients reported lower levels of physical activity, however, they also had lower caloric intake than parents of healthy children (the most marked differences between groups occurred in the area of physical activity).6
There has been some conflicting evidence though. In a study of 4,065 adolescents aged from 11 to 16 perceived stress in any year was not related to increases in waist circumference or BMI 1–4 years later, and there was no evidence that higher stress over the whole period was associated with greater gains in waist or BMI. However, waist and BMI were significantly higher in the moderate‐ and higher‐stress groups than the lower‐stress group across the whole 5‐year period.7 In another review, this one of college-age adults, it was found that stress could result in movements of weight up or down, according to the individual.8 This effect is likely to be due to behavioural and psychological tendencies and predisposition to anxiety and to whether the person is a habitual over- or undereater (and possibly whether they have other underlying metabolic disorders.)
Stress can result in movements of weight up or down according to the individual
The effects of stress on weight gain, especially given some of the unclear results, are also likely to be due to metabolic status and weight at baseline. In a study of 7965 British civil servants, in men, the effect of job strain on weight gain and weight loss was dependent on baseline BMI. In the leanest participants, stress was more likely to be related to weight loss, while those in the highest BMI group were more likely to gain weight (however, this effect wasn’t seen in women).9
After extreme stress, post-traumatic stress disorder (PTSD) can result. PTSD has been associated with a range of negative food and weight interactions. In a cohort of nearly 34000 service people, PTSD was associated with both disordered eating behaviours (vomiting, laxative use, fasting, over-exercise) and weight gain.10 In a more recent study, PTSD was associated with weight gain in both male and female veterans post-deployment, of an additional ~100g of weight gained per year compared to those without PTSD.11
PTSD was associated with both disordered eating behaviours and weight gain
Does social support protect against stress-induced weight gain?
In college students, social support has been demonstrated to modulate the effects of stress-eating on weight gain and this effect was seen most especially in males.12
Summary
Stress has a bi-directional relationship with many systems of the body and factors of health. Because of this, stress is now a known factor implicated in weight gain due to effects of stress hormones and their interplay with fat storage, inflammation, and secondarily to ‘stress-eating’ which encourages both overconsumption of food and poorer food choices.
Stress is now a known factor implicated in weight gain
References
1. Geiker NRW, Astrup A, Hjorth MF, Sjödin A, Pijls L, Markus CR. Does stress influence sleep patterns, food intake, weight gain, abdominal obesity and weight loss interventions and vice versa? Obesity Reviews. 2018;19(1):81-97.
2. Ilaria D, Elena G. Stress-Related Weight Gain: Mechanisms Involving Feeding Behavior, Metabolism, Gut Microbiota and Inflammation. Nutrition & Food Sciences. 2015.
3. Kim J, Kim HR. The relationship between increased job stress and weight gain: a 2-year longitudinal study. Occupational and Environmental Medicine. 2011;68(Suppl 1):A76-A7.
4. Klingberg S, Mehlig K, Johansson I, Lindahl B, Winkvist A, Lissner L. Occupational stress is associated with major long-term weight gain in a Swedish population-based cohort. International archives of occupational and environmental health. 2019;92(4):569-76.
5. Berset M, Semmer NK, Elfering A, Jacobshagen N, Meier LL. Does stress at work make you gain weight? A two-year longitudinal study. Scandinavian Journal of Work, Environment & Health. 2011;37(1):45-53.
6. Smith A, Baum A, Wing R. Stress and weight gain in parents of cancer patients. International journal of obesity. 2005;29(2):244-50.
7. van Jaarsveld CHM, Fidler JA, Steptoe A, Boniface D, Wardle J. Perceived Stress and Weight Gain in Adolescence: A Longitudinal Analysis. Obesity. 2009;17(12):2155-61.
8. Haidar SA, De Vries N, Karavetian M, El-Rassi R. Stress, anxiety, and weight gain among university and college students: A systematic review. Journal of the Academy of Nutrition and Dietetics. 2018;118(2):261-74.
9. Kivimäki M, Head J, Ferrie JE, Shipley MJ, Brunner E, Vahtera J, et al. Work stress, weight gain and weight loss: evidence for bidirectional effects of job strain on body mass index in the Whitehall II study. International Journal of Obesity. 2006;30(6):982-7.
10. Mitchell KS, Porter B, Boyko EJ, Field AE. Longitudinal Associations Among Posttraumatic Stress Disorder, Disordered Eating, and Weight Gain in Military Men and Women. American Journal of Epidemiology. 2016;184(1):33-47.
11. Buta E, Masheb R, Gueorguieva R, Bathulapalli H, Brandt CA, Goulet JL. Posttraumatic stress disorder diagnosis and gender are associated with accelerated weight gain trajectories in veterans during the post-deployment period. Eating behaviors. 2018;29:8-13.
12. Darling KE, Fahrenkamp AJ, Wilson SM, Karazsia BT, Sato AF. Does Social Support Buffer the Association Between Stress Eating and Weight Gain During the Transition to College? Differences by Gender. Behavior Modification. 2017;41(3):368-81.
