The optimal diet?

Last week’s article about carbs and nutrients in dairy generated much interest. This week, I’m going to develop this interest further with an article about something called “The Optimal Diet.” This will take us into the world of LCHF (Low Carb High Fat, also referred to as Low Carb Healthy Fat) – what is LCHF? and Who should be doing it?

I first heard about something called “The Optimal Diet” at an LCHF conference in Oslo, Norway, in November 2014. I was asked a question after my presentation about what I thought the optimal macronutrient ratios were. I replied that I don’t think setting macronutrient ratios is a good idea. We should just eat real food and then the macronutrient ratios will be what they will be. For non-diabetics, I still hold this view.

By the time I presented at the Cape Town, South Africa, LCHF conference in February 2015, I believed that diabetics (both types) should work to macronutrient ratios (as shared at the end of last week’s dairy note) and that those ratios should be 5% carbohydrate, 80-85% fat and 10-15% protein. For an average female, that’s about 100 calories of carbohydrate, 1,600-1,700 calories of fat and 200-300 calories of protein.

What changed over the winter of 2014-2015?

The Optimal Diet

A stranger who is now a friend, Dag Poleszynski, approached me after my presentation at the Oslo conference to share that there is a macronutrient ratio proposed as “The Optimal Diet” and that I would enjoy the work of a Polish doctor called Jan Kwasniewski. Kwasniewski was born in 1937 and worked in a military hospital as a dietician where he changed the diets of people to great effect and found one particular diet to be universally successful in establishing what he called “Optimal Health.” 

The “Optimal Health Diet”, or just “The Optimal Diet”, as it became known, is based on a very rigid formula, which says that the ideal proportion of protein, fat and carbohydrates should be:

1 gram of protein : 2.5-3.5 grams of fat : 0.5 grams of carbohydrate.

Protein is the starting point for this diet and the ideal protein intake was calculated by Kwasniewski on the basis of what he called “due body weight”. Due body weight, in kilograms, is estimated as a person’s height in centimetres minus 100 (± 10%). Thus, for a person 160 cm tall, a due body weight is 60 kg ± 6 kg. Kwasniewski then used the usual approximation that people need 1 gram of protein per kilogram of body weight to establish that the 160cm person needs 60 grams of protein ± 6 grams. The due body weight takes into account the protein need for where we want our weight to end up – not where it is now. (Taking height in cm and subtracting 100, by the way, is a pretty good rule of thumb for getting a weight in kg in the normal BMI range.)

To continue with our 160cm person/60 gram of protein person, s/he then needs 150 to 210 grams of fat and 30 grams of carbohydrate. Even with the 10% range allowed for due body weight, carbs barely change. At the upper end of the range, 66 grams of protein equates to 165 to 231 grams of fat, but still only 33 grams of carbohydrate. You can see how low the carb intake stays, even at the upper end of the range.

The Kwasniewski proportions for a 60kg person – 60 grams of protein, 150-210 grams of fat and 30 grams of carbohydrate – equate to the following calories: 240 calories of protein, 1,350-1,890 calories of fat and 120 calories of carbohydrate (Note 1).

As proportions of the diet, the lower fat intake works out at 14% protein, 79% fat and 7% carbohydrate. The higher fat intake works out at 11% protein, 84% fat and 5% carbohydrate.

The proportions remain exactly the same for different heights – only the calories and grams change. Let’s take my husband, Andy, at 6 foot (185cm). His due body weight would be 185-100 = 85kg and his protein need would be 85g (340 calories). His fat grams range would be 213-298 (1,913 – 2,678 calories). His carb limit would be 43g (170 cals). At the lower fat intake range (2.5 times protein), his proportions would be 14% protein, 79% fat and 7% carbohydrate. The higher fat intake is exactly the same as for the 160cm person – at 11% protein, 84% fat and 5% carbohydrate. (The formula proportions hold for any height).

I couldn’t find any guidance on when you would opt for the higher fat range and when the lower. I would suggest that the higher fat range would be for people who are slim and athletic. The lower fat range would seem best suited to those who need to lose weight and are less in need of fuel due to their activity levels.

A typical day on “The Optimal Diet”

I worked this out for an average female – keeping the 160cm height, which has been used above.

I did include a reasonable (200g) portion of milk at breakfast – not least because it’s difficult to have three meals a day on “The Optimal Diet”, because one runs out of protein and carbohydrate too easily. Breakfast was thus assumed to be 2 large eggs, 50g of bacon and 200ml whole milk. Knowing that butter (or coconut oil, or some fat) is essential to achieve the high fat ratios, I entered 90g of butter for lunch, but it wouldn’t be lunch. Some of this butter would likely have been added to the bacon and eggs for breakfast. ‘Optimal Dieters’ might have a bullet-proof coffee around lunch time – but, more often than not, they’re on two meals a day. The rest of the day’s butter would be added to the (175g) lamb and veg for dinner.

You can see that the portions are not huge – because the protein restriction limits the meat/eggs and the carb restriction limits veg/dairy. You can also see, as the dairy article mentioned last week, that you would rarely, if ever, have fish or chicken because the protein content would be too high. “The Optimal Diet” followers would constantly be looking for the fattiest meats.

Example – lower fat range (2.5x)




Carbs (g)

Fat (g)

Protein (g)

2 large eggs (Ref 1)






Bacon (Ref 2)






Milk, whole, 3.25% (Ref 3)







Butter, without salt (Ref 4)







Lamb (Ref 5)






Broccoli, raw (Ref 6)






Cauliflower, raw (Ref 7)






Beans, green raw (Ref 8)






TOTAL (may be rounding errors)





Target (lower fat range)





You wouldn’t count for long – you’d settle into a routine of bacon, eggs, maybe milk and butter for breakfast and meat/veg/butter for dinner – but this really is not my idea of fun. It’s a route I would take if I were diagnosed with diabetes, but it’s not something I would choose over how I eat now (which I love).

It’s also not as nutritious as how I eat (The Harcombe Diet®). In The Harcombe Diet club we have a “MyLocker” tool where daily intake can be entered and the tool automatically calculates macronutrients and micronutrients, all driven off the USDA all-foods database. This example above has the following deficiencies (this is the percentage of the Recommended Daily Allowances achieved by the foods above): Sodium 50%; Potassium 38%; Calcium 36%; Magnesium 32%; Iron 36%; Copper 58%; Zinc 73%; Manganese 28%; Vitamin D 25%; Vitamin E 32%; Thiamine 61% and Vitamin B6 87%.

This would explain why Dag Poleszynski downed a cocktail of supplements when we dined with him in Norway. It also means that you really need to be a fan of offal – to get the most nutrient dense bang for the buck for the real food that you do consume.

“The Optimal Diet” vs. LCHF

As recently as January 2017, a brilliant collaboration between Professor Tim Noakes and a Canadian doctor, Johann Windt, defined some terminology for low carbohydrate diets and LCHF. The full article can be seen here.

At the bottom of the first page, the authors give the following definitions:

“Though definitions of LCHF diets differ, the following three-tiered definition will be used in this paper.
Moderate carbohydrate diet (26–45% of daily kcal)
LCHF diet (<26% of total energy intake or <130 g CHO/day)
Very LCHF (ketogenic) diet (20–50 g CHO/day).”

What I called ‘hard-core’ LCHF in the dairy article, Tim and Johann call “very LCHF (ketogenic)” and they use the phrase “LCHF” to mean anything below 130g of carbohydrate a day.

Putting “The Optimal Diet” and “very LCHF (ketogenic)” diets together is fascinating. The former enables grams and calories for all three macronutrients to be calculated from protein; the latter enables grams and calories for all three macronutrients to be calculated from carbohydrate. If we assume that our 160cm person would be at the lower end of the 20-50g range for carbohydrate, knowing that carbohydrate should form 5% of total calorie intake, we can calculate calorie intake to be approximately 1,600 calories. That may shock some people! If 5%C/15%P/80%F ratios are used, fat then provides approximately 1,280 calories (142g) and protein provides 240 calories (60g). The protein requirement ends up the same (this should not be a surprise given that the carb/fat/protein proportions for “The Optimal Diet” ended up very similar to 5%C/15%P/80%F). Calories could be higher, because fat and protein can flex within a min 80% and max 15% range respectively. If 160g of fat and 55g protein were eaten, with the 5% carbohydrate, the approximate ratios would be 5% carb (just under)/82.5% fat/12.5% protein providing 1,740 calories in total.

Both “The Optimal Diet” and hard-core LCHF set food intake therefore and the intake is low. One drives from protein, the other from carbohydrate, but they end up at largely the same place. Arguably “The Optimal Diet” has more flexibility because of the fat range given.

We can then also deduce that LCHF (as opposed to “very LCHF”), as defined in the Noakes/Windt paper, cannot be in the proportions 5%C/15%P/80%F. This is because, if we take the upper limit of 130g of carbohydrate, at approximately 4 calories per gram, this delivers 520 calories. The daily intake would need to be 10,400 calories for 520 calories to be 5%! Noting the maximum 26% set for carbohydrate in the “LCHF” definition, and keeping the 60g protein, which seems to be consistent, the following grams and percentages of carb would make sense: 125g carb (25% of 2,000 calories a day); 60g protein (12%); and 140g fat (63%). Perhaps LCHF should mean Lower Carb Higher Fat?

Is this “The Optimal Diet”?

For diabetics yes; for everyone I’m not so sure. If you enjoy this rigidity and it works for you, that’s one thing, but I think that it’s too extreme and unnecessary for anyone who doesn’t need to go this far. As we have seen above, it can be nutrient deficient and it certainly takes away many of the pleasures of eating. The thought of life without cappuccinos and dark chocolate, if not red wine and berries, seems harsh – unless life has delivered you the cruel blow of diabetes, in which case these dietary options are your salvation. I also worry that people adopting hard-core LCHF (usually for weight reasons), who don’t need to, have nowhere left to go if very LCHF doesn’t work for them, or stops working for them.

Long before my first book was published (“Why do you overeat? When all you want is to be slim” 2004), I believed that the first principle of healthy eating should be “Eat real food.” The second principle should be “Choose that real food for the nutrients that it provides.” Given that there are essential fats and essential proteins (certain amino acids must be consumed) and that there are no essential carbohydrates (p275 here) and given that the richest sources of micronutrients are animal foods, we need to base our meals on animal foods. We certainly should not base our meals on starchy foods (as our governments advise) if we care about our weight and health. (This was a horrific realisation for a vegetarian to make, as I was at the time, but the facts are what they are. What we then choose to do is entirely up to us, which is why I still hold an empathy with, and understanding of, plant based choices.)

The Harcombe Diet® is specially focused on identifying and overcoming food cravings, so that people can make the right, healthy choices. While we are sugar addicts, we cannot do this. When we have overcome physical and emotional drivers for overeating, we are able to eat real food and choose that food for the nutrients it provides. We then naturally end up eating Lower Carb and Higher Fat because the most nutritious real foods are meat, fish, eggs, dairy and green leafy things. These are the ‘fat meals’, using The Harcombe Diet® terminology, although I didn’t hear about LCHF until 10 years after “Why do you overeat” was published.

Real food, without macronutrient restriction, allows all kinds of fish and meat (not just the fattiest ones), all kinds of dairy (not just the lower carb/protein ones) and far more variety with vegetables and fruit (ideally in season). With The Harcombe Diet® ‘carb meals’, I also enjoy some of my past veggie life favourites: crispy baked potatoes; porridge; butternut squash curry and brown rice. The big difference between having these now, and when they were my veggie staples, is that I know every time I choose a ‘carb meal’, a ‘fat meal’ would be more nutritious. But that’s my choice as a non-diabetic who loves food.

For a three day weekend in Norway and then for a week in South Africa, I ate with a number of people who were hard-core LCHF and I had the opportunity to see how they eat. I remember one morning sitting next to Professor Stephen Phinney at breakfast with a plate of fruit and I joked about my “sweeties”. His reply was “Why wouldn’t you?!” which I thought was both interesting and kind. He did not judge me for how I ate and intimated that – if one can enjoy the delights of fruit, why wouldn’t one?!

Note 1: This works with carbohydrate and protein being approximately 4 calories a gram and fat being approximately nine. These are not precise numbers, but they’re close enough for what we’re doing here with proportions. Where they will let you down is with calorie counting, but we don’t do that!