NICE-recommended weight management strategies include: Dietary intervention aiming for a 600 kcal/day deficit through reduced portion sizes, limiting energy-dense foods, and increasing fruit and vegetable consumption Physical activity building up to 150300 minutes of moderate-intensity aerobic activity weekly, plus muscle-strengthening activities on at least two days weekly, in line with UK Chief Medical Officers' guidelines [10] Behavioural approaches including self-monitoring, goal-setting, and addressing emotional eating patterns Commercial weight management programmes such as those meeting NICE quality standards (QS127) Very-low-calorie diets in specific circumstances, under clinical supervision and for limited periods For patients with a BMI 30 kg/m (or 27.5 kg/m in those of South Asian, Chinese, or other Asian family origin) who have not achieved adequate weight loss through lifestyle measures alone, pharmacological interventions may be considered

The muscle here is the vastus lateralis
Daily high doses of B12 may not likely cause harm in most people, but extremely high doses should possibly be avoided unless a healthcare professional prescribes it
If you're someone who has eliminated meat, dairy and fortified cereals from your diet, then it is possible that you may require supplements
Can you have B12 injections too often