Q) Is it OK to do one day of fats only with salad or veg and one day carbs alternating each day, or do you need to have a balance of both in a day?
A) Phase 2, in theory, does allow all meals to be carb meals, but people soon come to realise that fat meals are more satiating and weight loss is better with fat meals. For example, I so often hear people say “when I have porridge for breakfast I’m hungry a couple of hours later. When I have eggs for breakfast, I don’t feel hungry until early afternoon.”
You could try this fat/carb-meal pattern, but my worry would be that you would feel hungrier and less satiated on the carb-meal day and have more even energy and blood glucose levels on the fat-meal day. This could be an interesting experiment and help you to see for yourself what suits you best. In terms of weight loss, you could easily have 300g of carbohydrate on a carb-meal day and this would fill up glycogen stores for 24 hours. You would then empty this during the fat-meal day, but you would then be filling up the carb store room again as soon as you had emptied it. Rare exercise exceptions aside, you will only burn body fat when you don’t have carbs available for fuel. I don’t think this would happen often if you are ‘carb-loading’ one day and then ‘carb-fueling’ the next day.
You could always try this pattern and see if it works for you – in terms of hunger and weight loss – anything that works stick with! Anything that doesn’t – drop.