Neuromodulation as a treatment for food addiction in obese individuals

INTERVENTION: Group 1: placebo tRNS Group 2: active tRNS For tRNS: a) Dose administered: 1 mA for 10 minutes with 60 seconds ramp up and ramp down at the beginning and end of each stimulation session. b) Frequency of stimulation: 3 times a week for 2 weeks. c) Treatment will be administered by a trained Assistant Research Fellow d) Mode of administration: external head device (Starstim system‐ NE neuroelectrics) worn with electrodes on anterior cingulate cortex (4 cathodes at F7, T3, F8 and T4; 1 anode at Fz) e) Monitoring adherence using Case Report Forms CONDITION: Food addiction Obesity PRIMARY OUTCOME: Food craving will be assessed using the Oxford Leeds Questionnaire ( a validated computer task to measure food craving). Participants will be shown different paired presentation of food items (96 trials) and will be asked to select their most wanted food as quickly and as accurately as possible. Participants will not be aware of the measurement of their reaction time for the choices they make allowing a covert assessment for implicit motivational wanting of a particular food. ; ; SECONDARY OUTCOME: Day to day craving. Information on the food being craved for will be self‐reported on a daily basis in a questionnaire designed specifically for this study. Genetic markers. Blood sample will be collected to assess for TaqA1 alleles of dopamine D2 receptor and the opioid receptor OPRM1 gene. Liking of food. The validated Leeds‐Oxford questionnaire will be used to assess food liking. Participants will be shown a single food item and will be asked to rate "how pleasant would you find the taste of this food right now?" on a visual analogue scale (100‐unit). Psychological and behavioural outcomes. ; ; Participants will be given the following questionnaires. ; a) Addictive Tendency Questionnaire ‐ A 96‐item questionnaire measuring addictive tendencies across 12 domains. ; b) Intuitive Eating Scale (IES) ‐ A 21‐item questionnaire assessing eating in response to hunger and satiety cues rather than situational and emotional cues. ; c) Dutch Eating Behaviour Questionnaire (DEBQ) ‐ A 51‐item questionnaire assessing restrained, emotional and external eating. ; d) Mindful Eating Scale ‐ A 28‐item questionnaire measuring mindful eating (i.e., being aware of and appreciating the effects of food on the senses). ; e) Binge Eating Scale ‐ A 16‐item questionnaire assessing the presence of binge eating which may be indicative of an eating disorder. ; f) Behavioural Inhibition System (BIS) – Behavioural Activation System (BAS) questionnaire ‐ A 20‐item scale measuring the two motivational systems (inhibition and activation) underlying behaviour and affect. ; g) Hypomanic Personality Scale ‐ A 48‐item questionnaire assessing stable hypomanic traits. ; h) State/Trait Food Cravings Questionnaires ‐ A 36‐item questionnaire assessing temporal and situational states of food craving. ; i) Beck Depression Inventory‐II (BDI‐II) – A 21‐item self‐reported inventory for measuring severity of depression.* ; j) Beck Anxiety Inventory (BAI) – A 21‐item self‐reported inventory for measuring severity of anxiety.* ; ; * Participants will be asked to complete the BDI‐II and BAI after their physical and vital signs evaluation to screen for depression and anxiety. ; INCLUSION CRITERIA: aged 20‐60, BMI more or equals 30, Scores equals to or more than 3 on the Yale Food Addiction Scale ; Satiety. Electroencephalogram (EEG) using a 19 electrode cap on a Mitsar ‐201 system will be conducted. Participants will be asked to consume a liquid meal (Sanitarium Up and GO) until they reach satiety. ; Fasting EEG will be recorded and a second EEG will be conducted to assess 'peak satiety'. The participant will be allowed to leave the clinic thereafter and asked to return at 360 minutes for another follow‐up EEG. ; During this process, participants will also be asked to complete a numerical rate scale to assess hunger and satiety at fasting state, at peak satiety, 30, 45, 60, 90, 120, 180, 240, 300 and 360 minutes.