For almost half a century I’ve been saying that my phase shift diets are a paradigm shift from all other diets. And in that time, research has backed up most of my theories and claims. Following my diets you can maximize body composition and performance better than following any other diets, including Paleo, low carb, high protein, etc.

That’s because phase shift dieting prepares the body for whatever it comes up against. You can read up on my phase shift diets all over my site, including the info in the store, and in several of my articles.

One of the basic precepts behind my phase shift diets is that eating higher amounts of fat, coupled with low carbs, results in changes in your epigenome that in turn turns some genes on and other genes off with the ultimate result that pathways for using fat as a primary fuel are activated while others that makes carbs the primary fuel are downplayed. The overall result is that following my phase shift diets makes you fat adapted so that you use fat as your primary fuel. That sets you up for burning up body fat when dietary fat and calories consumed are lowered, while protein intake remains high. Since your body now depends on burning fat for energy, it will use body fat as a substitute for dietary fat. Because you’re sparing muscle, the weight you lose is mostly body fat.

Getting back to the research end, there’s a number of studies that have validated what I’ve been saying all along. That if you eat a high fat, high protein diet, you’ll burn off more body fat than if you follow other diets.

An example is one study published in 2011 (see below). While far from perfect since it only addresses the low carb phase of my phase shift diets, and the study only has the subjects on the diet for two weeks, not nearly long enough for all the benefits to show, it backs up one of the things that I’ve been saying all along about my diets and that’s the fact that it’s the best diet, among other benefits, for losing body fat.

In this study the authors “investigated if lipolytic rate is higher in subcutaneous adipose tissue of sedentary males when they consume a high fat diet as compared to a well-balanced diet. The present data suggest that interstitial glycerol concentrations are indeed higher in the absence of any difference in adipose tissue blood flow in sedentary overweight males on the high-fat diet as compared to the well-balanced diet. This is the first report of a higher in vivo lipolytic rate in subcutaneous adipose tissue in response to a higher-fat, LCD as compared to a balanced diet over the course of a day.”

Now we’re dealing here with sedentary (couch potato) males. Imagine the increase in lipolysis and fat burning that would occur if they got off their butts and actually did some decent training?

So far all of this deals with the low carb phase of my phase shift diets. There’s much more involved with this phase, and its interaction and benefits with the higher carb phase. Now some of this info is already on my site but there’s more that I’m still in the process of researching and writing.

For example, over 10 years ago a number of prominent researchers concluded that my phase shift diets, in other words becoming fat adapted from a high fat, low protein diet, with intermittent bouts of higher carbohydrates was not advantageous for athletes. In 2015 these researchers are starting to see the light as evidenced by some recent papers – see the citations and abstracts below.

These recent studies, while interesting, are only starting to see the impact of my phase shift on genetic and molecular levels. I’ll be explaining my theories in more detail in following articles over the next several months and thus spurring the research needed to validate the paradigm shift that my phase shift diets represent.

In future articles I’ll be delving into the genetic/epigenetics/metabolome/methylome/exposome/etc. and the associated pathways involved that connects my phase shift diets with improved body composition and performance. So stay tuned.

Metabolism. 2011 Jul;60(7):976-81. Epub 2010 Oct 30.
Increased adipose tissue lipolysis after a 2-week high-fat diet in sedentary overweight/obese men.
Howe HR 3rd, Heidal K, Choi MD, Kraus RM, Boyle K, Hickner RC.
Department of Biology, East Carolina University, Greenville, NC 27858, USA.


The purpose of this study was to determine if a high-fat diet would result in a higher lipolytic rate in subcutaneous adipose tissue than a lower-fat diet in sedentary nonlean men. Six participants (healthy males; 18-40 years old; body mass index, 25-37 kg/m(2)) underwent 2 weeks on a high-fat or well-balanced diet of similar energy content (approximately 6695 kJ) in randomized order with a 10-day washout period between diets. Subcutaneous abdominal adipose tissue lipolysis was determined over the course of a day using microdialysis after both 2-week diet sessions. Average interstitial glycerol concentrations (index of lipolysis) as determined using microdialysis were higher after the high-fat diet (210.8 ± 27.9 µmol/L) than after a well-balanced diet (175.6 ± 23.3 µmol/L; P = .026). There was no difference in adipose tissue microvascular blood flow as determined using the microdialysis ethanol technique. These results demonstrate that healthy nonlean men who diet on the high-fat plan have a higher lipolytic rate in subcutaneous abdominal adipose tissue than when they diet on a well-balanced diet plan. This higher rate of lipolysis may result in a higher rate of fat mass loss on the high-fat diet; however, it remains to be determined if this higher lipolytic rate in men on the high-fat diet results in a more rapid net loss of triglyceride from the abdominal adipose depots, or if the higher lipolytic rate is counteracted by an increased rate of lipid storage.


During the period 1985-2005, studies examined the proposal that adaptation to a low-carbohydrate (<25 % energy), high-fat (>60 % energy) diet (LCHF) to increase muscle fat utilization during exercise could enhance performance in trained individuals by reducing reliance on muscle glycogen. As little as 5 days of training with LCHF retools the muscle to enhance fat-burning capacity with robust changes that persist despite acute strategies to restore carbohydrate availability (e.g., glycogen supercompensation, carbohydrate intake during exercise). Furthermore, a 2- to 3-week exposure to minimal carbohydrate (<20 g/day) intake achieves adaptation to high blood ketone concentrations. However, the failure to detect clear performance benefits during endurance/ultra-endurance protocols, combined with evidence of impaired performance of high-intensity exercise via a down-regulation of carbohydrate metabolism led this author to dismiss the use of such fat-adaptation strategies by competitive athletes in conventional sports. Recent re-emergence of interest in LCHF diets, coupled with anecdotes of improved performance by sportspeople who follow them, has created a need to re-examine the potential benefits of this eating style. Unfortunately, the absence of new data prevents a different conclusion from being made. Notwithstanding the outcomes of future research, there is a need for better recognition of current sports nutrition guidelines that promote an individualized and periodized approach to fuel availability during training, allowing the athlete to prepare for competition performance with metabolic flexibility and optimal utilization of all muscle substrates. Nevertheless, there may be a few scenarios where LCHF diets are of benefit, or at least are not detrimental, for sports performance.



Blood glucose is an important fuel for endurance exercise. It can be derived from ingested carbohydrate, stored liver glycogen and newly synthesized glucose (gluconeogenesis). We hypothesized that athletes habitually following a low carbohydrate high fat (LCHF) diet would have higher rates of gluconeogenesis during exercise compared to those who follow a mixed macronutrient diet. We used stable isotope tracers to study glucose production kinetics during a 2 h ride in cyclists habituated to either a LCHF or mixed macronutrient diet. The LCHF cyclists had lower rates of total glucose production and hepatic glycogenolysis but similar rates of gluconeogenesis compared to those on the mixed diet. The LCHF cyclists did not compensate for reduced dietary carbohydrate availability by increasing glucose synthesis during exercise but rather adapted by altering whole body substrate utilization.


Endogenous glucose production (EGP) occurs via hepatic glycogenolysis (GLY) and gluconeogenesis (GNG) and plays an important role in maintaining euglycaemia. Rates of GLY and GNG increase during exercise in athletes following a mixed macronutrient diet; however, these processes have not been investigated in athletes following a low carbohydrate high fat (LCHF) diet. Therefore, we studied seven well-trained male cyclists that were habituated to either a LCHF (7% carbohydrate, 72% fat, 21% protein) or a mixed diet (51% carbohydrate, 33% fat, 16% protein) for longer than 8 months. After an overnight fast, participants performed a 2 h laboratory ride at 72% of maximal oxygen consumption. Glucose kinetics were measured at rest and during the final 30 min of exercise by infusion of [6,6-(2) H2 ]-glucose and the ingestion of (2) H2 O tracers. Rates of EGP and GLY both at rest and during exercise were significantly lower in the LCHF group than the mixed diet group (Exercise EGP: LCHF, 6.0 ± 0.9 mg kg(-1) min(-1) , Mixed, 7.8 ± 1.1 mg kg(-1) min(-1) , P < 0.01; Exercise GLY: LCHF, 3.2 ± 0.7 mg kg(-1) min(-1) , Mixed, 5.3 ± 0.9 mg kg(-1) min(-1) , P < 0.01). Conversely, no difference was detected in rates of GNG between groups at rest or during exercise (Exercise: LCHF, 2.8 ± 0.4 mg kg(-1) min(-1) , Mixed, 2.5 ± 0.3 mg kg(-1) min(-1) , P = 0.15). We conclude that athletes on a LCHF diet do not compensate for reduced glucose availability via higher rates of glucose synthesis compared to athletes on a mixed diet. Instead, GNG remains relatively stable, whereas glucose oxidation and GLY are influenced by dietary factors.