Overweight participants craved a greater variety of high-caloric high palatable foods than normal‐weight participants at both eating events and random non‐eating moments

Food craving in daily life: comparison of overweight and normal‐weight participants with ecological momentary assessment. A. Roefs  B. Boh  G. Spanakis  C. Nederkoorn  L. H. J. M. Lemmens  A. Jansen. Journal of Human Nutrition and Dietetics, August 20 2019. https://doi.org/10.1111/jhn.12693

Abstract
Background: The present study examined food cravings in daily life by comparing overweight and normal‐weight participants right before eating events and at non‐eating moments. It was hypothesised that overweight participants would have (i) more frequent, (ii) stronger and (iii) a greater variety of high‐caloric palatable food cravings, and also would (iv) consume more high‐caloric palatable foods, than normal‐weight participants.

Methods: Ecological momentary assessment (EMA) was used to assess food craving strength and frequency, variety of specific food cravings, and food intake. Fifty‐seven overweight and 43 normal‐weight adult participants were assessed at eating events and at an average of eight random non‐eating moments per day for 2 weeks. Foods were categorised as: high‐caloric high palatable foods (HCHP), fruits and salads, staple food dishes and sandwiches, and soups and yoghurts.

Results: Overweight participants reported more frequent HCHP food cravings specifically at non‐eating moments than did normal‐weight participants. Normal‐weight participants reported more food cravings for staple foods, specifically at eating events. Moreover, overweight participants craved a greater variety of HCHP foods than normal‐weight participants at both eating events and random non‐eating moments. No other significant between‐group differences were found.

Conclusions: The results highlight the importance for obesity interventions (i) to specifically target high‐caloric palatable food cravings that are experienced during the day and are not tied to eating moments and (ii) to aim for a reduction in the variety of high‐caloric palatable food cravings. It might be fruitful to deliver treatment aimed at reducing cravings via mobile devices because this allows for easy individual tailoring and timing of interventions.

Introduction
People eat not only to satisfy homeostatic hunger, but also to satisfy cravings and hedonic hunger 1, 2. Food cravings are common 3, and people often crave foods that are high in calories and low in nutritional value 4, 5. High‐caloric food intake has been associated with weight gain and obesity 6. Furthermore, sensitivity to the rewarding properties 7 and the reinforcing value 8 of palatable foods is stronger for people with a higher body mass index (BMI) than for those with a lower BMI. The present study aimed to investigate food cravings and intake of overweight (BMI ≥ 25 kg/m2) and normal‐weight (18.5 kg/m2 ≤ BMI < 25 kg/m2) people in daily life by means of ecological momentary assessment (EMA).
Previous research on food craving, mainly relying on retrospective self‐report (questionnaire) assessment, has found that overweight people have more frequent specific food cravings, mainly for high‐caloric foods, compared to normal‐weight people 4, 9-11. In addition, a meta‐analysis has shown that craving and food‐cue reactivity are significant predictors of eating behaviour and body weight 12, as well as of a reduction of perceived self‐regulatory success in dieting 13. Accordingly, an increased food craving appears to be an important aspect of obesity. However, retrospective self‐report assessment is subject to memory recall biases: more recent and more emotionally salient memories are disproportionately often recalled 14, 15. Investigating food cravings as they occur in daily life using EMA could lead to more ecologically valid insights.
During EMA, participants receive prompts on a mobile device (e.g. smartphone) several times a day to answer questions, for example regarding mood, social circumstances and food cravings, and/or are instructed to answer questions on their phone in predefined situations (e.g. when about to eat something). EMA has the advantage that data are obtained in the moment and in daily life (ecological validity) and are not affected by retrospective memory or response bias 14. Another advantage is that participants provide multiple assessments of the included variables, allowing researchers to analyse how the variables develop over time within a participant. Thus, ‘EMA aims to minimize recall bias, maximize ecological validity and allow study of microprocesses that influence behavior in real‐world contexts’ 15. EMA conducted via an electronic device may be especially suitable to assess food cravings because of the relatively short duration of such cravings 16.
EMA studies on food craving have increasingly been published in recent years. It was found that food cravings for sweet and salty snacks increased over the day, with a reduced coherence with hunger 17. In addition, a study focusing on snacks found that most reported snacks were high‐caloric (86%) and that craving intensity was positively associated with snack consumption 18. Studies focusing on dieters found that 17% 5 to 50% 19 of daily life food cravings resulted in dietary lapses. Interestingly, the strength and the frequency of food cravings were not related to dietary restraint 5, although dieters were more likely to give in to food temptations if the craving to eat was stronger 19. With regard to body weight, it was unexpectedly found that a group of people with obesity reported fewer unresisted food cravings compared to a lean group. However, within the obese group, the fraction of unresisted food craving was positively associated with BMI 20. Because that study employed only event‐related sampling (i.e. self‐initiated measurement at eating occasions), this may be a result of BMI‐related under‐reporting.
Another aspect of food craving relates to the variety of craved foods. Although previous research has linked food intake variety to obesity 21-23, not much is known about food craving variety. Sensory‐specific satiety has been suggested to explain the link between intake variety and obesity 24, 25: satiety occurs separately for each of the sensory characteristics of different kinds of foods. Accordingly, when a large variety of foods is consumed, it will take longer for satiety to set in, which may lead to increased intake 26. In general, food cravings and the subsequent intake of these craved foods are highly positively associated 4, 11, 27, 28, with one possibility being that food craving variety is also related to obesity.
Taken together, the present study investigates how food craving frequency, strength and variety, as well as food intake, are related to weight status. The study addresses the following hypotheses: overweight participants (i) report more frequent and (ii) stronger food cravings for high‐caloric palatable foods, (iii) they crave a greater variety of high‐caloric palatable foods and (iv) they consume more high‐caloric palatable foods compared to normal‐weight participants. In addition, the association between specific food cravings and food intake is investigated. Food craving frequency, strength and variety are investigated and compared separately for eating events (i.e. that were about to occur) and non‐eating moments. There are no specific a priori hypotheses about differences between eating events and non‐eating moments in terms of food craving frequency, strength or variety.