To evaluate the therapeutic efficacy and metabolic impact of a low energy diet (LED) in people with familial partial lipodystrophy and diabetes. Participants will be provided with a LED (total diet replacement) for 12 weeks, before the introduction of a stepped food transition. Metabolic effects will continue to be assessed for 1 year. In order to better understand why this intervention changes insulin sensitivity, we will also collect adipose and muscle tissue samples at baseline and 12 weeks into the intervention in participants willing to have these procedures performed. These samples will be used for histological, metabolite, gene expression and protein expression analyses.
Inclusion Criteria: * Familial Partial Lipodystrophy * Age \>= 18 yrs * T2DM * Willingness to check daily blood sugars * HbA1c between 53mmol(7%)- 108 mmol(12%) * Weight stable for 3 months * Capacity to consent Exclusion Criteria: * Pregnancy * Untreated thyroid dysfunction (patients who have been euthyroid on medication for at least 3 months can be included) * Use of medication adversely that affects diabetes control (e.g. steroids/ immunosuppressants/ certain antipsychotics) * Incapacity to give informed consent * History of an eating disorder/ purging behaviour * Previous gastric bypass/ banding * Use of Leptin Therapy * Untreated retinopathy