How can I eat less chocolate?

Answer: Try going for a brisk walk or some other exercise.

Appetite. 2011 Nov 10;58(1):387-392.

Brisk walking reduces ad libitum snacking in regular chocolate eaters during a workplace simulation.

Oh H, Taylor AH.

Abstract

Workplace snacking can contribute to obesity. Exercise reduces chocolate cravings but effects on chocolate consumption are unknown.

This study investigated the effect of brief exercise on ad libitum consumption during breaks in a computerised task. Seventy-eight regular chocolate eaters, age: 24.90±8.15years, BMI: 23.56±3.78kg/m(2) abstained for 2days. They were randomly assigned to one of four conditions, in a 2×2 factorial design, involving either a 15min brisk walk or quiet rest, and then computerised Stroop tasks with low or high demanding conditions, in three 180s blocks with a 90s interval. Throughout, a pre-weighed bowl of chocolates was available for ad libitum eating.

A two-way ANOVA revealed no interaction effect of exercise and stress on total chocolate consumption, or main effect of stress, but a main effect of exercise [F(1, 74)=7.12, p<.01]. Mean (SD) chocolate consumption was less (t(73.5)=2.69, 95% CI for difference 3.4-22.9, ES=0.61) for the exercise (15.6g) than control (28.8g) group. Exercise also increased affective activation, but there was no mediating effect of change in affect on chocolate consumption.

A brief walk may help to reduce ad libitum snacking in regular chocolate eaters.

Here’s a related study:

Appetite. 2009 Feb;52(1):155-60. Epub 2008 Sep 13.

Acute effects of brisk walking on urges to eat chocolate, affect, and responses to a stressor and chocolate cue. An experimental study.

Taylor AH, Oliver AJ.

Abstract

The study aimed to investigate the effects of an acute exercise bout on urges to eat chocolate, affect, and psychological and physiological responses to stress and a chocolate cue.

Following 3 days of chocolate abstinence, 25 regular chocolate eaters, took part, on separate days, in two randomly ordered conditions, in a within-subject design: a 15-min brisk semi-self-paced brisk walk or a passive control. Following each, participants completed two tasks: the Stroop colour-word interference task, and unwrapping and handling a chocolate bar.

Chocolate urges [State Food Cravings Questionnaire (FCQ-S); Rodríguez, S., Fernández, M. C., Cepeda-Benito, A., & Vila, J. (2005). Subjective and physiological reactivity to chocolate images in high and low chocolate cravers. Biological Psychology, 70, 9-18], affective activation [Felt Arousal Scale; Svebak, S., & Murgatroyd, S. (1985). Metamotivational dominance: a multimethod validation of reversal theory constructs. Journal of Perception and Social Psychology, 48, 107-116], affective pleasure/valence [Feelings Scale; Hardy, C. J., & Rejeski, W. J. (1989). Not what, but how one feels: the measurement of affect during exercise. Journal of Sport and Exercise Psychology, 11, 304-317], and systolic/diastolic blood pressure (SBP/DBP) were assessed throughout.

Exercise reduced chocolate urges and there was a trend towards attenuated urges in response to the chocolate cue. Exercise also attenuated SBP/DBP increases in response to the stressor and chocolate cue. The effects on urges varied across the dimensions of the FCQ-S.

How can I grow my aging hippocampus?

Answer. Exercise!

Exercise training increases size of hippocampus and improves memory

Kirk I. Erickson, et al

Abstract

The hippocampus shrinks in late adulthood, leading to impaired memory and increased risk for dementia. Hippocampal and medial temporal lobe volumes are larger in higher-fit adults, and physical activity training increases hippocampal perfusion, but the extent to which aerobic exercise training can modify hippocampal volume in late adulthood remains unknown. Here we show, in a randomized controlled trial with 120 older adults, that aerobic exercise training increases the size of the anterior hippocampus, leading to improvements in spatial memory. Exercise training increased hippocampal volume by 2%, effectively reversing age-related loss in volume by 1 to 2 y. We also demonstrate that increased hippocampal volume is associated with greater serum levels of BDNF, a mediator of neurogenesis in the dentate gyrus. Hippocampal volume declined in the control group, but higher preintervention fitness partially attenuated the decline, suggesting that fitness protects against volume loss. Caudate nucleus and thalamus volumes were unaffected by the intervention. These theoretically important findings indicate that aerobic exercise training is effective at reversing hippocampal volume loss in late adulthood, which is accompanied by improved memory function.

This  article explains the results in more detail:

Train your Muscles, Embiggen your Hippocampus