The effect of a 12-week low carbohydrate vs a high carbohydrate weight loss diet on oxidative stress and inflammation in New Zealand defence force personnel.

This randomised controlled trial (RCT) is a 12-week dietary intervention comparing a low carbohydrate, high fat (LCHF) way of eating with a control mainstream-nutrition-guided group in a group of navy personnel from the New Zealand Defence Force (NZDF). The LCHF diet is defined as <130g carbohydrates per day; 15-25% of total energy from protein; >60% of total energy from fat. Participants will be required to consume 3 meals a day (or the addition of more meals as long as it does not exceed their energy threshold) for 12 weeks. Participants will be expected to prepare their own food but will be provided with detailed instructions / resources / recipes to assist them. Resources provided to them will be a combination of those designed specifically for this research, and associated websites for recipes and other information (www.ditchthecarbs.com and www.dietdoctor.com). The dietitian and nutritionist will be administering the intervention. Participants will be required to track their dietary intake for a 2-week period at two time-frames (weeks 1-3, and weeks 6-8) on a free smart phone app called Easy Diet Diary. This will be sent to the research team who has access to the partner application, Foodworks for analysis. Research assistants that are nutrition-trained will be undertaking group sessions with participants every two weeks, where they will use food frequency questionnaires to measure adherence.