Dr Michael Mosley has published a Keto version of his "Fast" diet series in book form, serialised in the Daily Mail for the January "dieting season" and online on his web site.
I decided to give it a try, as it's written in British English with familiar foods and takes the interesting approach of targetting a calorie reduction explicitly, alongside carbohydrate restriction. In the first phase it presents meal plans of 2 or 3 meals per day broadly designed around keeping daily protein at 50g or more, carbs below 50g and calories around 800-1000. None of the meal plan days are actually as low as the stated 800 kcal/day. For our Transatlantic friends the 50g of carbs is digestible carbohydrate excluding fibre, what the US would call "net carbs".
After one week I am writing this and can report a weight loss of 4.6 lbs / 2.1 kg. Blood glucose this morning was 4.6 mmol/l (83 mg/dl) and ketones 1.5 mmol/litre, so the approach certainly works for me. My wife has a smaller weight loss of 3.8 lbs, eating approximately the same as me.
We have prepared and cooked all the food for the recipes and not used any of the shakes or soups that are available for the "Fast 800" series of diets. Generally speaking we eat the three meals between 9 or 10 am and try to finish by 6pm, in part to avoid any hunger issues around 5pm.
I have tracked the meals using Cronometer to see how the macro and micronutrient intake looks on this restricted calorie intake. The macros are broadly in line with the recipe values in the boook, which are wriiten by Mosley's wife Dr Clare Bailey. There were a number of shortfalls in the micronutrients though, with tpyically 85% of daily targets being met. I shall discuss these individually below. At this stage I think some of it may be missing data, but some of it is a deficiency in the diet which would probably also apply to my standard diet. Here's what the Cronometer web site shows for one of the days (ignore the water intake, I don't reliably log water or black coffee intake) :-
Starting with the lipids, the Omega-3 value above includes a fish oil based supplement I take which has 360 mg of EPA and 240 mg of DHA. This accounts for ~38% of the omega 3 value and avoids a deficit.
Omega-6 typically runs low on this diet as there is a little olive oil used but no sunflower or other high PUFA oils. I don't feel it necessary to increase the 3-6 g/day intake.
Moving on to protein the list of amino acids is generally filled out to at least 100% with the inclusion of eggs, salmon, chicken and similar foods that contain high quality protein.
In the Vitamins we start to see some gaps occur regularly. Vitamins D & K are taken as a supplement and without that D would always be deficient and K often so. The B vitamins often show deficiency which I have chose to correct with a daily teaspoon of nutritional yeast flakes reinforced with B12. Vitamin E is persistently low, and not easy to find in foods. While some rapeseed or sunflower oils appear to contain an amount of E it is at a level that would involve too many calories or too much omega-6 intake. We have added some nuts and seeds to help with this, but it's a work in progress.
When it comes to minerals the Calcium and Potassium are persistently low. As my wife has a broken wrist she is now supplementing with calcium to offset this. I am a little unsure if the actual intake is low, or if we have a data problem with minerals in the food databases. More investigation required. Marnesium would be low if I wasn't supplementing with 300 mg of magnesium as citrate. The sodium intake is good and I beleive this will help offset any potassium issues based on what Dr Stephen Phinney has said about the action of the kidneys on a keto diet.
So overall we have had initial success with 3 meals a day of 1000 +/- 150 kcal/day following the book's eating plan. We haven't looked at switching to two (larger) meals per day and it is later in the diet that we may switch to 4 days of higher calorie intake and 3 days at the above restricted intake.
