Emotional Eating Moderates the Relationship between Implicit Measures of Attitudes and Chocolate Consumption

Emotional eaters tend to eat more when emotionally aroused and their food–related actions are associated with lack of control. Two studies tested the hypothesis that implicit measures of attitudes would be more strongly associated with the dietary behaviour of emotional eaters. In both Study 1 ( N = 32) and Study 2 ( N = 101), participants completed the DEBQ sub–scale of emotional eating and implicit measures of attitude, explicit attitude and behaviour measures concerning chocolate consumption. In both studies, high emotional eaters were more likely than low emotional eaters to eat in line with their implicit measures of attitudes. The relationship between implicit measures of attitudes and food intake varies as a function of emotional eating style. Copyright © 2010 John Wiley & Sons, Ltd.

An experimental test of control theory-based interventions for physical activity

OBJECTIVES

To provide an experimental test of control theory to promote physical activity.

DESIGN

Parallel groups, simple randomized design with an equal chance of allocation to any group.

METHODS

Participants not meeting recommended levels of physical activity but physically safe to do so (N = 124) were recruited on a UK university campus and randomized to goal-setting + self-monitoring + feedback (GS + SM + F, n = 40), goal-setting + self-monitoring (GS + SM, n = 40), or goal-setting only (GS, n = 44) conditions that differentially tapped the key features of control theory. Accelerometers assessed physical activity (primary outcome) as well as self-report over a 7-day period directly before/after the start of the intervention.

RESULTS

The participants in the GS + SM + F condition significantly outperformed those in the GS condition, d = 0.62, 95% CI d = 0.15-1.08, and marginally outperformed those in the GS + SM condition in terms of total physical activity at follow-up on the accelerometer measure, d = 0.33, 95% CI d = -0.13 to 0.78. The feedback manipulation (GS + SM + F vs. GS + SM and GS) was most effective when baseline intentions were weak. These patterns did not emerge on the self-report measure but, on the basis of this measure, the feedback manipulation increased the risk that participants coasted in relation to their goal in the first few days of the intervention period.

CONCLUSIONS

Using behaviour change techniques consistent with control theory can lead to significant short-term improvements on objectively assessed physical activity. Further research is needed to examine the underlying theoretical principles of the model. Statement of contribution What is already known on this subject? Interventions incorporating more techniques that are consistent with control theory are associated with larger positive changes in health behaviours and related outcomes (see reviews by Dombrowski et al., ; Michie et al., ). However, none of the studies included in these reviews were explicitly based on control theory (see Prestwich et al., ). What does this study add? This study is the first experimental test of the cumulative effects of behaviour change techniques as proposed by control theory. Intervening on all aspects of the feedback loop noted by control theory leads to more change; however, the risk that some participants coast in relation to their set goal is significant. This approach increased physical activity more in those with weaker intentions pre-intervention.

Partner- and planning-based interventions to reduce fat consumption: randomized controlled trial

OBJECTIVE

The research tested the efficacy of partner- and planning-based interventions to reduce dietary fat intake over a 6-month period.

DESIGN

Randomized controlled, blinded, parallel trial.

METHODS

A computer randomization feature was used to allocate council employees (N = 427, of which 393 completed baseline measures) to one of four conditions (partner + implementation intentions, partner-only, implementation intentions, and control group) before they completed measures at baseline and follow-ups at 1, 3, and 6 months post-baseline. Outcome measures were comprised of validated self-report measures of dietary fat intake (saturated fat intake, fat intake, ratio of 'good' fats to 'bad' fats); psychosocial mediators (enjoyment, intention, self-efficacy, social influence, partner support); weight and waist size (baseline and 6 months only).

RESULTS

Data from 393 participants were analysed in accordance with intention-to-treat analyses. All intervention groups reported greater reductions in fat intake than the control group at 3 months. The partner-based groups increased the ratio of 'good' fats to 'bad' fats at 3 and 6 months and lost more inches on their waist, versus the non-partner groups. The impacts of the partner-based manipulations on outcomes were partially mediated by greater perceived social influences, partner support, and enjoyment of avoiding high-fat foods. The partner-based interventions also increased intention and self-efficacy. However, the effects in this study were typically small and generally marginally significant.

CONCLUSIONS

Partner-based interventions had some positive benefits on dietary-related outcomes at 3 and 6 months. Support for implementation intentions was more limited.

Exploring the question-behaviour effect: randomized controlled trial of motivational and question-behaviour interventions

PURPOSE

Measuring intentions and other cognitions to perform a behaviour can promote performance of that behaviour (the question-behaviour effect, QBE). It has been suggested that this effect may be amplified for individuals motivated to perform the behaviour. The present research tested the efficacy of combining a motivational intervention (providing personal risk information) with measuring intentions and other cognitions in a fully crossed 2 × 2 design with an objective measure of behaviour in an at-risk population using a randomized controlled trial (RCT).

METHODS

Participants with elevated serum cholesterol levels were randomized to one of four conditions: a combined group receiving both a motivational intervention (personalized cardiovascular disease risk information) and a QBE manipulation (completing a questionnaire about diet), one group receiving a motivational intervention, one group receiving a QBE intervention, or one group receiving neither. All participants subsequently had the opportunity to obtain a personalized health plan linked to reducing personal risk for coronary heart disease.

RESULTS

Neither the motivational nor the QBE manipulations alone significantly increased rates of obtaining the health plan. However, the interaction between conditions was significant. Decomposition of the interaction indicated that the combined condition (motivational plus QBE manipulation) produced significantly higher rates of obtaining the health plan (96.2%) compared to the other three groups combined (80.3%).

CONCLUSIONS

The findings provide insights into the mechanism underlying the QBE and suggest the importance of motivation to perform the behaviour in observing the effect.

STATEMENT OF CONTRIBUTION

What is already known on this subject? Research has indicated that merely asking questions about a behaviour may be sufficient to produce changes in that or related behaviours (referred to as the question-behaviour effect; QBE). Previous studies have suggested that the QBE may be moderated by the individual's motivation to change the behaviour, i.e., the QBE will only produce increases in the behaviour among those with strong motivation to perform the behaviour. However, no study has directly tested this prediction by manipulating motivation and examining impacts on the QBE. What does this study add? The present study tested the individual and combined effects of a motivational and a QBE intervention in a fully crossed design using a randomized controlled trial (RCT) and showed that: a combined intervention significantly increased behaviour. effect partially mediated by cognitions.

Relations between implicit and explicit measures of attitudes and measures of behavior: evidence of moderation by individual difference variables

The moderating role of individual difference variables (Self-Reported Habit Index [SRHI], Need for Cognition [NFC]) on relationships between implicit (Implicit Association Test [IAT], Extrinsic Affective Simon Test [EAST]) or explicit measures of attitude and behavior is assessed in two studies. A dissociation pattern is found on self-report diary measures of behavior. In Study 1, the EAST-behavior relationship is moderated by SRHI; explicit measures of the attitude-behavior relationship are moderated by NFC. In Study 2, the IAT-behavior relationship is moderated by SRHI; explicit measures of the attitude-behavior relationship are moderated by NFC. Higher levels of SRHI and NFC are associated with stronger relationships between the implicit or explicit measures of attitude and the measure of behavior. In Study 2, the SRHI x IAT interaction is replicated for an objective behavior measure. Implications for understanding the relationship between implicit and explicit measures of attitudes and measures of behavior are discussed.

Effect of viral load on the outcome of herpes zoster

Varicella-zoster virus (VZV) is a member of the Herpesviridae family, primary infection with which causes varicella, more commonly known as chicken pox. Characteristic of members of the alphaherpesvirus subfamily, VZV is neurotropic and establishes latency in sensory neurons. Reactivation of VZV causes herpes zoster, also known as shingles. The most frequent complication following zoster is chronic and often debilitating pain called postherpetic neuralgia (PHN), which can last for months after the disappearance of a rash. During episodes of acute zoster, VZV viremia occurs in some, but not all, patients; however, the effect of the viral load on the disease outcome is not known. Here we describe the development of a highly specific, sensitive, and reproducible real-time PCR assay to investigate the factors that may contribute to the presence and levels of baseline viremia in patients with zoster and to determine the relationship between viremia and the development and persistence of PHN. VZV DNA was detected in the peripheral blood mononuclear cells (PBMCs) of 78% of patients with acute zoster and in 9% of healthy asymptomatic blood donors. The presence of VZV in the PBMCs of patients with acute zoster was independently associated with age and being on antivirals but not with gender, immune status, extent of rash, the age of the rash at the time of blood sampling, having a history of prodromal pain, or the extent of acute pain. Prodromal pain was significantly associated with higher baseline viral loads. Viral load levels were not associated with the development or persistence of PHN at 6, 12, or 26 weeks.

Linkage disequilibrium assessment via log-linear modeling of SNP haplotype frequencies

Analyses of high-density single-nucleotide polymorphism (SNP) data, such as genetic mapping and linkage disequilibrium (LD) studies, require phase-known haplotypes to allow for the correlation between tightly linked loci. However, current SNP genotyping technology cannot determine phase, which must be inferred statistically. In this paper, we present a new Bayesian Markov chain Monte Carlo (MCMC) algorithm for population haplotype frequency estimation, particularly in the context of LD assessment. The novel feature of the method is the incorporation of a log-linear prior model for population haplotype frequencies. We present simulations to suggest that 1) the log-linear prior model is more appropriate than the standard coalescent process in the presence of recombination (>0.02 cM between adjacent loci), and 2) there is substantial inflation in measures of LD obtained by a "two-stage" approach to the analysis by treating the "best" haplotype configuration as correct, without regard to uncertainty in the recombination process.

Developmental regulation of DNase I-hypersensitive sites in Dictyostelium discoideum

We have studied two regions of Dictyostelium discoideum chromatin and identified several DNase I-hypersensitive sites in these regions. One of these sites is located about 300 to 500 bases upstream of the transcriptional start site of a gene that is expressed at all stages of development. This site is present in both vegetative cells and postaggregation cells. Another hypersensitive site is associated with a gene that is expressed only after the multicellular stage. This site is located about 400 bases upstream of the start site, and it is present only in postaggregation cells. Thus, much like higher eucaryotes, D. discoideum contains DNase I-hypersensitive sites that may be involved in the regulation of the genes with which they are associated.

Regulation of the capacity for O6-methylguanine removal from DNA in human lymphoblastoid cells studied by cell hybridization

Hybrids were made between a ouabain-resistant, thioguanine-resistant human lymphoma line able to remove O6-methylguanine from its DNA (Mex+) and human lymphoblastoid lines deficient in this capability (Mex-). The formation of hybrids was confirmed by chromosomal analysis. Hybrid cells had an O6-methylguanine removal capacity per mole of guanine about one third to one half that of the Mex+ parents, i.e., about the same per cell. Cell hybrids removed the same amount of the alkylation adduct 3-methyladenine as did their parents per mole of guanine, i.e., about twice as much per cell. Although the cell hybrids had intermediate resistance to the cytotoxic action of N-methyl-N'-nitro-N-nitrosoguanidine used to induce O6-methylguanine and 3-methyladenine, there is evidence that the ability to remove O6-methylguanine and resistance to the cytotoxic effect of N-methyl-N'-nitro-N-nitrosoguanidine are dissociable characteristics.

Repair of neocarzinostatin-induced deoxyribonucleic acid damage in human lymphoblastoid cells: possible involvement of apurinic/apyrimidinic sites as intermediates

Neocarzinostatin (NCS) induces repair in a xeroderma pigmentosum lymphoblastoid line deficient in the ability to repair DNA damage induced with (acetoxyacetyl-amino)fluorene. Repair was demonstrated by the induction of repair synthesis and by the disappearance of NCS-induced single-strand breaks and/or alkaline-labile sites in DNA. Estimation of NCS-induced repair patch size, based on the density shift induced in DNA by extensive shear after incubation of treated cells in medium with bromodeoxyuridine or by calculation from the extent of restoration of DNA sedimentation profiles in alkaline sucrose gradients and the amount of repair synthesis measured by the BND cellulose method, indicated that only a few nucleotides were inserted per repaired region. NCS-treated bacteriophage T7 DNA requires incubation with alkaline phosphatase to make it a substrate for DNA polymerase I. NCS-reacted T7 DNA, even after phosphatase treatment, is not a substrate for a DNA polymerase alpha obtained from human lymphoma cells. NCS-treated T7 DNA did serve as a substrate for the DNA polymerase alpha when incubated with an apurinic/apyrimidinic (AP) endonuclease with associated 5'-3'-exonuclease activity. The results suggest that NCS-induced AP sites could be intermediates for the in vivo repair synthesis.