The 4 Phases of a Well-Formulated Ketogenic Diet For Weight Loss

What Is a Well-Formulated Ketogenic Diet?

The term “well-formulated ketogenic diet (WFKD)” was first coined by researchers Dr. Steve Phinney and Dr. Jeff Volek, the founders of Virta Health. The goal of a well-formulated ketogenic diet is not only achieving a state of nutritional ketosis but doing so in a way that supports optimal health and can be safely followed indefinitely.

Principles and characteristics of the WFKD include

• Carb intake at a level that maintains ketone levels between 0.5-4.0 mmol/L, the range for nutritional ketosis. This involves a personalized approach based on individual carb tolerance.
• Moderate protein intake
• High fat intake
• Non-starvation-level calorie intake (a minimum of 1200 calories per day). Use our keto calculator to calculate your calorie and macronutrient needs.
• Sufficient electrolytes (sodium, magnesium, potassium)
• Primarily whole foods
• Delicious, satisfying, and easy to stick with long term

Research on WFKDs for Weight Loss & Health Improvement

A WFKD can be extremely effective for achieving weight loss and blood glucose control, along with lower levels of inflammatory and cardiovascular risk markers. Indeed, many people who follow a WFKD have reported these benefits, among others.

Within the past few years, Virta Health has published several impressive studies looking at outcomes of people with type 2 diabetes following a WFKD long term ( 1, 2,  3).

In a pilot study, overweight type 2 diabetic adults were randomly selected to receive nutritional guidance based on either an ad-lib (non-calorie-restricted) WFKD or a low-fat “Plate Method” approach. All interactions were conducted via an online format ( 1).

At the end of the 8-month study:

• The WFKD groups' HbA1c — which reflects a person's average blood glucose level over a period of 2-3 months — decreased twice as much as the Plate Method group's did
• 10 out of 11 people in the WFKD group lost more than 5% of their body weight, while this only occurred in 2 out of 8 people in the Plate Method group
• The dropout rate among the WFKD group was only 8% (1 person) vs 46% (6 people) in the Plate Method group
• Based on self-reported data, participants in the WFKD group felt better on their diet and found it easier to stick with compared to the Plate Method group

In a larger study, 262 overweight type 2 diabetic patients were randomized to receive standard nutrition education and care or a WFKD that included health coaching and medical management ( 3).

Throughout the study, researchers reported significantly greater improvements in weight and cardiometabolic markers in the WFKD group compared to the group who received usual care.

A few of the changes experienced by WFKD participants after one year:

• HbA1c decreased from 7.6% to 6.3%, on average
• Weight decreased by 13.8 kg (30 lbs), on average
• Insulin therapy was eliminated or dosage significantly reduced in 93% of patients, and most oral medications were reduced in dosage or eliminated altogether
• Insulin resistance decreased by 55%, on average
• The inflammatory marker C-reactive protein (CRP) decreased by 39%, on average

These results demonstrate that a WFKD can lead to long-term metabolic improvements. Moreover, becoming keto-adapted improves insulin sensitivity and allows people to easily access their own fat stores for energy.

The 4 Phases of a Well-Formulated Ketogenic Diet

The four phases of a WFKD reflect the changes in energy (calorie) intake and expenditure during different stages of weight loss through weight maintenance.

One of the most important things to note is that on a keto diet, fat always supplies the majority of calories during every phase.

This chart from the Virta Health blog illustrates the changes in calorie intake and expenditure that would be expected to occur in a hypothetical 5'6” woman as she loses 40 pounds on a WFKD.

Phase 1: Induction

The Induction phase represents the first few weeks of a WFKD, when fat loss is most rapid. In fact, body fat can supply almost half of energy (calorie) needs in some cases.

A WFKD doesn't involve intentional calorie restriction — mainly because it isn't necessary. There's compelling evidence that being in ketosis suppresses appetite ( 4,  5). Indeed, most people find that they automatically eat less on a keto diet due to increased satiety and the ability to maintain blood glucose and insulin levels within a healthy low range. Moreover, because they're consuming fewer calories than they need, stored body fat is released to meet the rest of their energy requirements.

Average energy distribution during the induction phase:

The woman in our example is eating very few carbs and a moderate amount of protein. At first glance, her fat intake of 91 grams might not seem to provide enough energy for someone on a keto diet. However, her body is actually using more than 200 grams of fat per day for energy — and at this point, it's a combination of dietary fat and stored body fat.

Phase 2: Weight Loss

During the Weight Loss phase, body fat continues to decrease, although at a slower rate.

Our hypothetical woman is now eating about 200 more calories and burning about 350 fewer calories than during the Induction phase. However, she's still in an energy deficit and continues using fat as her main energy source.

Average energy distribution during the weight loss phase:

Carb intake increases slightly (Remember that this is total carbs; net carbs may still be under 20 grams), while average protein intake remains the same. Most of her energy is now coming from dietary fat. However, body fat still provides almost a third of her energy needs, which are decreased overall now that she's at a lower weight.

Phase 3: Premaintenance

In Premaintenance, weight loss continues to slow down as the calorie deficit narrows.

Average energy distribution during the premaintenance phase:

Again, total carb intake increases by about 10 grams while protein remains constant at 90 grams. By this point, dietary fat is providing the overwhelming majority of her energy needs, although body fat is still making a small contribution.

Phase 4: Maintenance

In the Maintenance phase, our successful keto dieter is no longer losing body fat because she's achieved her goal weight and is energy balance.

During weight maintenance, this woman's average calorie intake matches her average calorie expenditure. The number of calories that she consumes vs. burns may vary from day to day, and sometimes these numbers won't be exactly the same on each side. However, the differences will average out, and her weight will remain stable because she'll be in overall energy balance.

Average energy distribution during the maintenance phase:

Total carb intake increases to 60 grams per day (Net carbs may be anywhere from 25-45 grams per day, depending on the amount of fiber consumed). Average protein intake has remained stable at 90 grams throughout the weight loss transition and will stay at this level during maintenance. Dietary fat is now providing about 70% of her energy requirement, whereas previously a combination of dietary fat and body fat supplied 70-80% of energy needs.

Caveats and Personalization of the 4 Phases of a Well-Formulated Ketogenic Diet

Different macronutrient ratios

Although a WFKD is always high in fat, the distribution of carb, protein, and fat may vary somewhat throughout the different phases. Dr. Phinney and Dr. Volek have discussed the importance of individualization, as some people may be able to tolerate slightly more carbs and protein than others.

Your ideal macronutrient ratio may fall within any of these ranges during weight loss and maintenance:

• 5-12% carbs
• 15-25% protein
• 65-80% fat (from dietary fat in maintenance and a combination of dietary and stored body fat during weight loss)

Rate of weight loss

It's an undeniable fact that people lose weight at different rates, regardless of macronutrient distribution and calorie intake.

Factors that affect how quickly weight loss occurs include:

• Age
• Gender
• Starting weight and body composition
• Weight loss and dieting history
• Health disorders (hypothyroidism, PCOS, lipidema, etc.)
• Genetics

You may have one or more factors associated with slower weight loss and have a tougher time making progress. Fortunately, for many people, keto and low-carb diets offer the best chance for ultimate success.

The appetite-suppressing effects of nutritional ketosis may vary

Studies have shown that in general, a WFKD controls hunger and provides satiety better than other diets do. However, the degree to which this occurs differs among individuals and is often strongest in the initial phase of the diet. Although the woman in our example only consumed about half of the calories needed to maintain her weight — which allowed her to use body fat for the remainder — you may not be satisfied eating 1300-1400 calories every day, even at the beginning. On the other hand, you'll almost certainly end up eating fewer calories than needed for weight maintenance.

Calories in vs calories out?

Although a calorie deficit is necessary for weight loss, it's not as simple as calories in vs. calories out. Here's a quote from Dr. Steve Phinney's excellent 2014 presentation, Optimizing Weight & Health with an LCHF Diet:

“It's much more complex than that issue. It's not just how many calories come in, but how many calories you feel compelled to eat, which determines what comes in. And getting into nutritional ketosis gives people permission to burn quite a bit of their body fat stores.”

The importance of micronutrients

A WFKD contains healthy, well-balanced meals that provide optimal amounts of vitamins and minerals in addition to an appropriate macronutrient distribution.

Basing your meals on minimally processed animal and plant foods that are naturally high in fat and low in carbs is key. Check out these free Ketogenic Diet Meal Plans, which are in line with WFKD principles.