Effect of a weight-loss program on mental stress–induced cardiovascular responses and recovery

Solid or Liquid Food-The Intention to Eat Different Foods under Negative Emotions

Food can relieve an individual's emotions, especially for emotional eaters. For instance, chewing alleviates negative emotions. Solid and liquid foods comprise a huge part of our daily lives, and the chewiness of solid foods is always high. Here, we explored whether people, especially emotional eaters, have higher eating intentions to eat highly chewy foods while experiencing negative emotions by comparing their eating intentions toward solid and liquid foods. To this end, we conducted a survey of 147 participants using a questionnaire (Experiment 1) to understand their eating intention toward five types of food (purple potato, maize, black soya bean, mango, and soybean; each food group contained a solid food and a liquid food) while experiencing negative emotions. The results showed that individuals exhibited higher eating intention toward solid food compared with liquid food while experiencing negative emotions. In Experiment 2, we selected 85 and 65 high-emotional and low-emotional eaters, respectively, and further explored their preference for solid foods. The results showed that individuals with high levels of emotional eating exhibited higher intentions toward solid food while experiencing negative emotions compared with those with low levels of emotional eating. In conclusion, this study proved that individuals' higher eating intentions toward highly chewable food were pronounced among individuals with high levels of emotional eating under negative emotion conditions.

Effect of short-term weight loss on mental stress-induced cardiovascular and pro-inflammatory responses in women

Epidemiologic evidence links psychosocial stress with obesity but experimental studies examining the mechanisms that mediates the effect of stress on adiposity are scarce. The aim of this study was to investigate whether changes in adiposity following minimal weight loss affect heightened stress responses in women, and examine the role of the adipokine leptin in driving inflammatory responses. Twenty-three overweight or obese, but otherwise healthy, women (M age = 30.41 ± 8.0 years; BMI = 31.9 ± 4.1 kg/m(2)) completed standardized acute mental stress before and after a 9-week calorie restriction program designed to modify adiposity levels. Cardiovascular (blood pressure and heart rate) and inflammatory cytokines (leptin and interleukin-6; IL-6) responses to mental stress were assessed several times between baseline and a 45-min post-stress recovery period. There were modest changes in adiposity measures while the adipokine leptin was markedly reduced (-27%) after the intervention. Blood pressure reactivity was attenuated (-3.38 ± 1.39 mmHg) and heart rate recovery was improved (2.07 ± 0.96 Bpm) after weight loss. Blood pressure responses were inversely associated with changes in waist to hip ratio post intervention. Decreased levels of circulating leptin following weight loss were inversely associated with the IL-6 inflammatory response to stress (r = -0.47). We offered preliminary evidence suggesting that modest changes in adiposity following a brief caloric restriction program may yield beneficial effect on cardiovascular stress responses. In addition, reductions in basal leptin activity might be important in blunting pro-inflammatory responses. Large randomized trials of the effect of adiposity on autonomic responses are thus warranted.

Body mass index-modified relationship of chronic mental stress with resting blood pressure during 5 years in Japanese middle-aged male workers

BACKGROUND

Chronic mental stress has been reported to be directly or inversely proportional to blood pressure (BP). To explain this inconsistent relationship, we assumed effect-modification by body mass index (BMI).

METHODS AND RESULTS

We examined 1,673 Japanese male local government employees who were not taking antihypertensive drugs or had no history of cardiovascular disease. BP and BMI were recorded at yearly health checkups. Exposure to mental stress, smoking, drinking, exercising, and salty taste were checked by questionnaire in 1997 and 2002. The main effect and interaction of stress and BMI on the averages and changes of resting systolic and diastolic BPs over the 5 years were assessed by a general linear model by adjusting for confounders. Obesity (BMI ≥25kg/m(2)) was significantly related with higher average systolic and diastolic BPs (P<0.001, P<0.001, respectively), whereas mental stress was not, showing a significantly different relationship dependent on BMI (P for interaction =0.002, 0.004): a significant and directly proportional association with systolic and diastolic BPs (P=0.001, 0.001) in the obese, but borderline significant and inversely proportional association (P=0.07, 0.08) in the lean. Only BMI was significantly related to the degree of BP change.

CONCLUSIONS

Whereas BMI was proportionally associated with BP, BMI was a modifier which, depending on its level, inverted the direction of the association between chronic mental stress and resting BP.

The effect of overweight/obesity on cardiovascular responses to acute psychological stress in men aged 50-70 years

BACKGROUND

To determine the effect of adiposity in males aged 50-70 years on cardiovascular responses to acute psychological stress.

METHODS

Lean (BMI 20-25 kg/m(2)) (n = 21) and overweight/obese (BMI 27-35 kg/m(2)) (n = 21) men aged 50-70 years were subjected to psychological stress. Systolic blood pressure, diastolic blood pressure, heart rate, total peripheral resistance, and cardiac output were measured by a Finometer during resting (60 min), stress (30 min), and recovery (90 min).

RESULTS

The lean group had a significantly higher SBP stress reactivity when compared to the overweight/obese group (51.5 ± 3.7% vs. 41.0 ± 2.9% (mean ± SEM) ; p < 0.05). A significant effect of time was observed for systolic blood pressure, diastolic blood pressure, heart rate, total peripheral resistance, and cardiac output (p < 0.0001 for all). There were significant time × body type interactions for systolic blood pressure, diastolic blood pressure, heart rate, total peripheral resistance, and cardiac output (p < 0.05 for all). Total peripheral resistance during recovery was higher in the lean compared to the overweight/obese group (p < 0.05). In the lean group, systolic and diastolic blood pressure variability remained elevated after stress (p < 0.05) but returned to resting levels in the overweight/obese group (p > 0.05).

CONCLUSION

Moderate adiposity in men was associated with reduced systolic blood pressure % reactivity, total peripheral resistance, and blood pressure variability after psychological stress. Overweight/obese men appear to be at no greater risk of unfavorable cardiovascular responses to stress.

Cardiovascular and cortisol reactions to acute psychological stress and adiposity: cross-sectional and prospective associations in the Dutch Famine Birth Cohort Study

OBJECTIVE

In recent analyses of data from a large community sample, negative cross-sectional and prospective associations between cardiac stress reactivity and obesity were observed. The present study reexamined the association between cardiovascular reactivity and adiposity in the Dutch Famine Birth Cohort, with the additional aim of examining the association between cortisol reactivity and adiposity.

METHODS

Blood pressure, heart rate, and salivary cortisol were measured at rest and in response to standard laboratory stress tasks in 725 adults. Height, weight, waist-and-hip circumference, and skinfold thickness were measured. Between 4 to 7 years later, 460 participants reported current height and weight. Obesity was defined as a body mass index of 30 kg/m(2) or higher.

RESULTS

Those with a greater body mass index (β = -0.39 beats per minute (bpm)), waist-to-hip ratio (β = -0.15 bpm), and triceps and subscapular skinfold thicknesses (β = -1.0 and -1.8 bpm) or who were categorized as obese (-3.9 bpm) displayed smaller cardiac reactions to acute stress (all p < .001). With the exception of waist-to-hip ratio, the same negative associations emerged for cortisol reactivity (all p ≤ .01). In prospective analyses, low cardiac reactivity was associated with an increased likelihood of becoming or remaining obese in the subsequent 4 to 7 years (odds ratio = 1.03, p = .01). All associations withstood adjustment for a range of possible confounders.

CONCLUSIONS

The present analyses provide additional support for the hypothesis that it is low not high cardiac and cortisol stress reactivity that is related to adiposity.

Weight change in control group participants in behavioural weight loss interventions: a systematic review and meta-regression study

Background

Unanticipated control group improvements have been observed in intervention trials targeting various health behaviours. This phenomenon has not been studied in the context of behavioural weight loss intervention trials. The purpose of this study is to conduct a systematic review and meta-regression of behavioural weight loss interventions to quantify control group weight change, and relate the size of this effect to specific trial and sample characteristics.

Methods

Database searches identified reports of intervention trials meeting the inclusion criteria. Data on control group weight change and possible explanatory factors were abstracted and analysed descriptively and quantitatively.

Results

85 trials were reviewed and 72 were included in the meta-regression. While there was no change in control group weight, control groups receiving usual care lost 1 kg more than control groups that received no intervention, beyond measurement.

Conclusions

There are several possible explanations why control group changes occur in intervention trials targeting other behaviours, but not for weight loss. Control group participation may prevent weight gain, although more research is needed to confirm this hypothesis.

Effects of fruit consumption on body mass index and weight loss in a sample of overweight and obese dieters enrolled in a weight-loss intervention trial

OBJECTIVE

Fruit and vegetable consumption is an important part of a healthy diet and assumed to aid in the reduction of energy intake and body weight. Fruits and vegetables may display differential effects on weight and weight loss; however, the effects of the two food groups have rarely been investigated separately.

METHODS

The present study focused on the effects of fruit consumption on body weight and weight loss in a sample of 77 overweight and obese dieters enrolled in an intervention program. Food consumption was assessed at baseline by food diaries and after the introduction of nutrition software through electronic food records. Body weight and additional physiologic outcomes were assessed three times, once before the intervention and again at the 3- and 6-mo follow-ups.

RESULTS

Vegetable and fruit consumption differed in their associations with body weight and weight loss. Although vegetable consumption increased as a result of the intervention (P<0.01), fruit consumption did not. However, only fruit consumption was associated with body mass index, showing an inverse relation with body weight in cross-sectional and longitudinal analyses (r=-0.27 to -0.44). The relation between fruit consumption and body weight remained significant after controlling for age, gender, physical activity level, and daily macronutrient consumption (DeltaR(2)=0.06-0.13). Further, increases in fruit consumption were associated with subsequent weight loss, controlling for the same covariates (DeltaR(2)=0.05-0.07).

CONCLUSION

The results indicate unique contributions of fruit consumption to the management of body weight and indicate that a separation of effects for fruit and vegetable food groups may be warranted.

Body mass index, abdominal adiposity, obesity, and cardiovascular reactions to psychological stress in a large community sample

OBJECTIVE

To examine the association between adiposity and the magnitude of cardiovascular reactions to acute psychological stress cross-sectionally and prospectively in a large community sample.

METHODS

Blood pressure and heart rate (HR) were measured at rest and in response to a brief time-pressured mental arithmetic stress in 1647 adults. At the same session and 5 years later, height, weight, waist and hip circumference were measured and body mass index (BMI) and waist-hip ratio were computed. Obesity was defined as a body mass index of > or = 30 kg/m(2).

RESULTS

Contrary to expectations, the most robust and consistent results to emerge from cross-sectional analyses were negative associations between all three measures of adiposity and HR reactivity; those with greater BMI and waist-hip ratios and those categorized as obese displayed smaller HR reactions to stress. In prospective analyses, high HR reactivity was associated with a reduced likelihood of becoming obese in the subsequent 5 years.

CONCLUSIONS

Our analyses suggest that it is low, not high, HR reactivity that is related to adiposity. Low HR reactivity, probably by reflecting generally blunted sympathetic nervous system reactions to challenge, may be a risk marker for developing obesity.