​​​​The best diet for longevity and overall health has been found to be one which keeps insulin levels low which in practical terms has low protein, low sugar and higher fat content.  The following diets are all considered to fall into this general category with the Perfect Health Diet taking into account our circadian nutrient intake being the most optimum choice for longevity.

  • The Banting Diet


       This diet was the first published diet which limited carbohydrate (sugars and starches). William Banting published a booklet Letter On Corpulence in 1864 which described his cure for obesity. He had received this prescription for eating from Dr. William Harvey. Banting did not limit his calories but only severely restricted his carbohydrate intake. He lost a tremendous amount of weight within a year and remained slimmer for the remainder of his days (he was 62 when he began the diet).

  • The Mackarness Diet

       The low carb diet was explained and refined in a book by Dr. Richard Mackarness entitled Eat Fat and Grow Slim published in 1960. In his book Dr. Mackarness lays out a practical slimming diet which is based on the hypothesis that sugar and starch are stored as fat in obesity-prone people while in naturally slim people these constituents are burned readily for energy. 

  • The Optimal Diet

        A low carb diet movement began in Poland with Dr. Jan Kwasniewski. He published a book called Optimal Nutrition which advocated a specific Protein : Carb  : Fat ratio of 1.0 : 0.7 : 2.5 by weight. The amount of protein (in grams) was determined by a person's ideal weight. Once calculated, the amount of carbs (in grams) would be in a range of 50-70% of protein. The amount of fat was calculated at approximately 2.5 times the weight of protein. 

  • The Atkins Diets

        Dr. Robert Atkins first popularized his version of the low carb diet in 1972. It was very strict with limiting carbs to under 50 grams per day. The rest of the diet was composed of protein and fat. In 2001 Dr. Atkins published a revised diet called the Age-Defying Diet. This diet was based on a macro-nutrient distribution of approximately 65% protein and fats (eggs, meats, cheese, nuts, etc.), 25% complex carbs (vegetables, grains, beans, etc.) and 10% simple carbs such as fruit, milk, sweets, etc.

  • The Paleo Diets

        The paleo diets generally claim to follow the dietary pattern of hunter-gatherers. These diets vary quite widely among their adherents but typically are high in protein and low  in starch. Since they are modeled after pre-agricultural living, there are no grains or dairy included in the diet. The advantage of this diet is that it will naturally keep blood glucose and insulin levels low. The main concern with this type of diet is that it may over emphasize protein intake. Too much protein will also provoke an insulin response which is counter productive.  A diet for ultimate health should not be based on a certain snapshot of history but rather on sound scientific principles.

  • The Rosedale Diet

        Dr. Ron Rosedale in recent times has published his own version of the low carb diet aptly named The Rosedale Diet.  The scientific reasoning behind this diet is to maintain low blood glucose and thus low insulin levels since these substances accelerate aging and disease if they are chronically elevated. The main distinctive feature of this diet is that it is also a low or adequate protein diet. This is based on the fact that the amino acids of digested protein also causes an insulin response which is harmful to the cells and organs of the body. Dr. Rosedale advocates a low protein intake of about 50-75 grams per day. Carbohydrate intake should be less than 20% of calories with the remainder of the diet consisting of mostly unsaturated fat. This diet is very commendable in that it is based on sound scientific principles. However, it is extreme in its carbohydrate restriction which may be counter productive.

  • The Perfect Health Diet

        One of the most recent low-carb diets is the Perfect Health Diet developed by Paul Jaminet. This diet is probably the least restrictive of the low-carb, high-fat diets. Dr. Jaminet describes his diet this way:

"By weight, the diet works out to about 3/4 plant foods, 1/4 animal foods. By calories, it works out to about 600 carb calories, primarily from starches; around 300 protein calories; and fats supply a majority (50-60%) of daily calories. "

The PHD food chart looks like this.

Recently Paul Jaminet and Ron Rosedale have debated their differing views on carbohydrates in the diet. While Dr. Rosedale views any amount of carbohydrate as unnecessary and any amount of blood glucose as toxic, Dr. Jaminet believes that a certain range of carbs is optimal in the diet. He expresses this as follows:

"I am sympathetic to the broad perspective that underlies Dr Rosedale’s diet. Both our diets are low-carb, low-protein, and high-fat, and studies of longevity are the biggest factor motivating the recommendation to eat a fat-rich diet.

However, Dr Rosedale takes low-carb and low-protein dieting to an extreme that I think is not well supported by the evidence.

Dr Rosedale’s direct attempt at refuting our diet consists mainly of two claims:

Lower blood glucose is better than higher blood glucose.
The way to lower blood glucose is by eating fewer carbs.

Neither claim is supported. Mortality is a U-shaped function of blood glucose and blood glucose levels around 90 to 100 mg/dl are healthiest, not low blood glucose levels. Moreover, the diet that delivers the lowest blood glucose levels is a high-carb, insulin-sensitizing diet, such as the Kitavans eat, not a low-carb diet.

If I truly believed Dr Rosedale’s argument for lower blood glucose, he would have persuaded me to eat a high-carb Kitavan-style diet. However, I am not persuaded.

I believe that:

Optimal blood glucose levels are in the 90 to 100 mg/dl range. High-carb diets cause below-optimal levels of blood glucose, especially during fasts. (Indeed, high-carb dieters routinely experience hunger and irritability during long fasts.) Very low-carb diets cause elevated blood glucose due to the body’s efforts to conserve glucose by suppressing utilization. Excessive suppression of glucose utilization is unhealthy.
A 20% carb diet, while not optimal for every single person, is healthy for nearly everyone. Twenty percent may be the best single prediction of the optimal carb intake for the population as a whole. Even diabetics can do well eating 20% carbs.

And that is why we recommend moderate consumption of safe starches."

  • The Circadian Diet

        The final diet we will examine is the Circadian Diet. This diet takes into account our circadian (daily) physiological rhythms which orchestrate all the timely bodily functions. The most powerful circadian influence is the day/night cycle. The circadian cycles are controlled by the pineal gland in the brain which regulates melatonin levels to orchestrate the various biological processes when they are required.

The next most powerful circadian influence is the foods we eat. This is explained in great detail in Dr. Sidney Baker's book The Circadian Prescription. The circadian diet is not concerned as much with the amount of carbohydrate consumed daily but more crucially when it is consumed. Dr. Baker explains how most of our protein should be consumed for breakfast and lunch while the bulk of our carbohydrates should be eaten after 4:00 PM in the afternoon. Dr. Baker reasons that blood glucose levels need to be highest in the evening so that the liver can perform all of it's many functions during the night while we are asleep. 

Dr. Baker acknowledges that it is harmful to have elevated blood insulin levels which respond to carbohydrate intake, but that if carbs are saved for the evening meal then insulin is elevated only once per day rather than many times throughout the day.

This is confirmed with studies which prove that blood glucose and lipid levels are optimized when carbohydrates are consumed in the evening (study).  The study makes the following statements and conclusions:

"Concentrating carb intake in the evening meal was also more healthy, and resulted in an increase in the secretion of the 'good fat hormone' adiponectin. Adiponectin helps the muscles to absorb more nutrients from the bloodstream. In addition, the concentration of inflammatory proteins such as CRP, TNF-alpha and Interleukine-6 decreased more in the experimental group than in the control group. The ‘morning’ insulin and glucose levels were lower in the experimental group than in the control group, and their concentration of HDL, 'good cholesterol', was higher.

"We have demonstrated improvement in hunger/satiety status, persistence in the weight loss process, better anthropometric outcomes, improved insulin sensitivity, improvement in metabolic syndrome parameters, less inflammation and hormonal changes, following simple carbohydrate manipulation", the researchers conclude. "Our results provide a scientific basis for proposing possible dietary alternatives that may be beneficial for people suffering from obesity, insulin resistance, and the metabolic syndrome and experiencing difficulties in maintaining a weight loss diet over the long term."

This is in direct opposition to the diets which promote early carbohydrate consumption for energy.


We agree with Dr. Jaminet (PHD) that moderate carbohydrate intake is preferred over a zero or extremely low carbohydrate intake. However, many people may continue to struggle with keeping a strict carb intake at roughly 20% of calories. 

It would seem to be an ideal solution to limit most carbohydrate intake to the evening meal when our body is best designed to optimally use those carbohydrates. Thus we get the optimum health outcome by following the circadian prescription for health and longevity.

So what constitutes a healthy diet? Most of our calories should come from fat-rich protein sources such as eggs, fatty meat, dairy, and fish. The best oils to consume are coconut, olive, avocado and fish. Avoid all vegetable oils including corn, soy, sunflower, safflower, cottonseed, canola, margarine, butter substitutes, etc. Avoid hydrogenated or partially hydrogenated oils. 

Most vegetables should be cooked to make them more nutritious. Raw carrots are very good as well.

Safe starches are rice and potatoes. Starches from cereal grains should be limited. Be careful with soy due to its phyto-estrogen content which may unbalance the testosterone to estrogen sex hormones.

Move the vast majority of your starches and to the evening after 4 PM. Drink plain filtered water, coffee, tea, and milk. Fruit juices and soft drinks have too much sugar and should be avoided as much as possible. Do not eat within a few hours before bed.

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