Metabolic confusion, also known as “calorie shifting,” is a restrictive diet where the daily calorie intake shifts between high and low days. This is an effort to "confuse" the metabolism into staying in a consistent fat-burning state.
In recent years, metabolic confusion has been in the same conversation circles as intermittent fasting, keto, and other fad diets. Practitioners boast about the fat-burning benefits, but others suggest that there isn't enough evidence to verify its effectiveness.
Let's take at what metabolic confusion is, how it works, and the potential benefits and effects of the diet.
What Is the Metabolic Confusion Diet?
Metabolic confusion is different from other calorie-restrictive diets because there is no set way to eat on the plan. Practitioners alternate calorie intake based on high and low calories days. The amount of calories consumed daily varies from person to person, based on factors like body type, and weight loss goals.
The resting metabolic rate (RMR) is the number of calories that the body burns at rest. The varying calories keep the RMR high and consistently burning calories, resulting in loss of body fat and weight.
A 2017 study on the benefits of intermittent energy restriction found that eating a restrictive diet has positive health benefits for obese and overweight practitioners, but can be harmful to those in “normal” weight ranges.
Like other calorie-restrictive diets, constant calorie fluctuation and restriction can't be maintained long-term. At some point, your metabolism adjusts, and your weight loss may slow or stop. Although it’s natural, it’s also frustrating. To break this plateau, you have to adjust your diet or exercise routine so you can start losing weight again.
In the next section, we’ll look at how body type plays a part in burning calories.
What are the 3 Metabolic Types?
The concept of soma types or "metabolic body types," was introduced during the 1940s by Dr. William Herbet Shelton. He defined the human body in three categories: ectomorphic, mesomorphic, and endomorphic. The classifications define the body’s leanness or ability to burn calories.
Shelton based this concept on the three germ layers within the human body: ectoderm, endoderm, and mesoderm. Today, health professionals classify people into three body types:
Ectomorph: The body is lean, has low body fat, and has small and long bones. Ectomorphs have a high metabolism and burn calories at a faster rate than the other body types.
Mesomorph: Mesomorphs have a solid, medium-sized frame. The body type burns calories at a high enough rate that the body has a muscular athletic look.
Endomorph: Endomorphs tend to be stalky and curvy in structure. The body type carries more weight than the two other body types, due to a slower-burning metabolism.
Each body type responds to restrictive diets differently, based on calorie intake and type of training.
For example, ectomorphs are the classic "hard gainers." They need to eat a heavy carb diet and strength train with moderate to heavy weights, to increase muscle mass and size.
Conversely, for endomorphs, high-intensity workouts like HITT training paired with a low-carb diet may be more appropriate for more effective fat-burning.
Regardless of your body type, fitness goals can be achieved by setting realistic expectations, and consistency in nutrition and fitness.
What Is Carb and Calorie Cycling?
Cycling carbs is becoming increasingly popular within the fitness industry as a way to control body weight. This method of tracking is used by fitness competitors, bodybuilders, Crossfitters, fighters, and other athletes.
The method involves alternating high carbohydrate days with medium and low consumption days. There are several carb cycling methods that can be applied including daily, weekly, or monthly changes. This depends on your training schedule and body composition goals.
This type of strategy may be more suitable for most people because the body doesn't feel as calorically depleted for days on end. Dieters can have relief every other day or every other week to stay motivated.
A typical week of carb cycling could look like this:
- Day 1: High Carbohydrates
- Day 2: High Carbohydrates
- Day 3: Moderate Carbohydrates
- Day 4: Moderate Carbohydrates
- Day 5: Low Carbohydrates
- Day 6: Low Carbohydrates
- Day 7: Low Carbohydrates
One challenging aspect of carb cycling is the preparation involved. Meals must be planned for the day or days ahead. Planning around your training schedule will streamline getting in meals and calories after workouts.
Is Intermittent Fasting the Same as Metabolic Confusion?
Metabolic confusion and intermittent fasting are similar in that they are calorie restrictive. intermittent fasting isn’t technically a diet. It’s an eating style where people cycle long periods of fasting with shorter eating windows. This helps regulate weight by keeping the body in a caloric deficit and raising the RMR. When food is consumed, the body uses it as fuel as opposed to being stored as fat.
For example, with the 16:8 method, a person fasts for 16 hours and then eats meals within an 8-hour window.
Research has sown that intermittent fasting is beneficial for obese dieters. One such study compared a group of obese dieters on a continuous energy restriction diet, to a group on an intermittent fasting diet. The calories restricted group experienced more issues related to depleted energy. The intermittent fasting group lost 5% more weight and some participants reported increases in energy.
Besides weight loss, intermittent fasting has other health benefits.
Benefits of Intermittent Fasting
Incorporating intermittent fasting can be a huge lifestyle adjustment. People who choose to commit to this eating style say it’s worth it for these potential benefits.
Fasting can also improve blood sugar control and reduce the risk for type 2 diabetes. However, research is limited, and the effects of intermittent fasting on insulin resistance may vary depending on a person’s weight and gender.
Fasting has been shown to reduce oxidative stress and inflammation, which are major factors in the development of several diseases like cardiovascular disease and cancer.
Intermittent fasting is known for stimulating cellular repair. This compared with reduced inflammation and oxidative stress and improved blood sugar control can improve brain function. This can reduce the risks of ailments like Alzheimer’s disease and depression.
Metabolic confusion and intermittent fasting have similarities but require different degrees of calorie restraints. Based on your lifestyle and goals, the best method is the one you can do the most consistently. Some people find fasting easier than tracking calories or macros for metabolic confusion, while others don’t prefer fasting. If your goal is weight loss, it’s important to remember that an overall calorie deficit is key.
What Are the Potential Benefits of a Metabolic Confusion Diet?
Before starting the metabolic confusion diet, or any diet, first, consult with your doctor or a licensed nutritionist. They will guide you on your weight loss journey and can help with questions, and overcoming plateaus, and roadblocks.
You should pair your nutrition plan with a regular fitness program. The body can't lose weight from diet alone. At some point, the body will plateau. Lifting weights can help the body burn fat and add lean muscle.
More Flexibility in Eating
The metabolic confusion diet doesn't have many concrete rules like other calorie-restrictive diets. Daily calorie intake can alternate between every other day or every few days of consuming low carb and high carbohydrate meals. The flexibility lets you still enjoy life and adjust calorie intake for fun life events.
Increases in Satiety and Satisfaction
Satiety is the amount of time that the body experiences fullness. Consuming a high protein diet is effective for weight loss due to appetite regulation. Eating lots of proteins and fats can help keep the body feeling full longer.
Can Metabolic Confusion Help With Weight Loss?
Restricting calories and keeping the body in a deficit for a period of time will cause weight loss. Since the metabolism is running high, the body burns fat. However, more studies need to be conducted on the benefits and consequences of eating on caloric restriction and fasting diets.
Once the body reaches a plateau, goals and caloric intake should be re-evaluated and adjusted. When the weight loss goal is achieved, dieters will need to eat on a "maintenance diet" to maintain the current weight.
What Are the Downsides of Metabolic Confusion?
While there are benefits to eating a calorie-restrictive diet like lowered blood pressure and increased metabolism, there are downsides like sustainability. The body can't maintain fluctuation between high and low-calorie consumption or remain in a prolonged calorie deficit for extended periods.
For example, a study conducted by the Journal of the International Society of Sports Nutrition found that nutrient deficiencies like iron depletion are common in female athletes that are vegetarian, vegan, or under consume calories. A lack of nutrients can affect hormones in the body, causing decreases in estrogen and progesterone levels during the menstrual cycle.
When transitioning off a restrictive diet and moving back into regular eating, calories should be increased gradually. It's important to seek the guidance of a doctor or a licensed nutritionist to minimize quick increases in weight gain.
In general, restrictive diets like these might be best when done on a short term basis, and then you can switch back to a more sustainable and healthy nutrition plan.
Is a Metabolic Confusion Diet Safe?
Metabolic confusion is generally safe for people without any underlying health conditions or history of eating disorders.
Everyone’s body may handle this diet differently. It’s important to pay attention to mood and energy levels. If they are too low you may need to adjust your calorie levels. Fatigue, irritation, and binge eating are signs that your calorie is too low. Undereating can ultimately deter your goals.
Successfully executing metabolic confusion requires you to track calories or macronutrients strictly. You can monitor them using a calorie tracking app or in a spreadsheet. Dieters may see short-term success results in weight loss, but there is still not enough research to determine the long-term effects.
Is Metabolic Confusion Ideal for Endomorphs?
The metabolic confusion diet could help endomorphs lose weight. While there are studies that have been conducted on calorie-restrictive diets, there isn’t enough evidence to confirm the full benefits of the metabolic confusion diet.
Using strategies like meal prep and scheduling daily meals can help regulate portion sizes, macronutrient timing, and eating consistency. This means scheduling several small meals throughout the day to keep the body fueled. "Tupperware life" may not be for everyone, but preparing meals in advance will ensure that you have food ready when it's time to eat.
A Sample Metabolic Confusion Plan
In order to effectively implement a metabolic confusion plan, it’s important to understand how to fuel your body appropriately on high carbohydrate and high calorie days, as well as on low carbohydrate and low calorie days.
Carb Cycling Sample Week
Let’s take someone who requires 2,000 calories daily as an example.
On high carb days, they would need to consume about 65% of their calories from carbohydrates, or 325 grams of carbs.
Moderate carb intake might look like about 45% of calories coming from carbs, or 225 grams.
Low carb days would require about 20% of caloric intake from carbs, or about 100 grams.
It’s best to follow a high carb diet for two days, followed by two days of moderate carb intake, and lastly a few days of low carbs.
For that person who needs 2,000 calories per day, here’s what the week might look like.
Monday: 325 grams of carbs
Tuesday: 325 grams of carbs
Wednesday: 225 grams of carbs
Thursday: 225 grams of carbs
Friday: 100 grams of carbs
Saturday: 100 grams of carbs
Sunday: 100 grams of carbs
While 325 grams of carbs might sound like a lot, it’s relatively simple to achieve this target with a bit of planning.
For example, a breakfast consisting of a bagel, a banana, and a glass of milk will provide nearly 95 grams of carbs.
Add in a cup of rice at both lunch and dinner and you’ll get another 90 grams.
After that, a few snacks whether it be an energy bar, fruit smoothie, or some crackers and cheese will easily help you reach your target.
Low carbohydrate days may seem a bit challenging, however, if you focus on eating more protein, fat, and vegetables, you can definitely meet your goal.
Low carbohydrate meals should emphasize protein sources such as meat, poultry, or fish, as well as plenty of vegetables and healthy fats. Low carbohydrate snack options might consist of raw veggies, cheese, jerky, hard boiled eggs, or olives, for example.
Calorie Cycling Sample Week
When it comes to calorie cycling, someone who requires 2,000 calories daily should progressively reduce caloric intake over the course of the week to properly follow the metabolic confusion diet.
Monday: 2000 calories
Tuesday: 2000 calories
Wednesday: 1700 calories
Thursday: 1700 calories
Friday: 1400 calories
Saturday: 1400 calories
Sunday: 1400 calories
To best help you stay on track with the metabolic confusion diet, it’s helpful to log the food you’re consuming on a daily basis.
There are several apps that make it super simple to track total calories and macronutrients. Lime myfitnesspal, for example.
The Bottom Line
There still isn't enough research to confirm the effectiveness of metabolic confusion.
Although you may see results, you have to consider sustainability and the long-term effects of eating a restrictive diet.
There's no magic diet that will instantly shed pounds in a few weeks. Nutrition plays a primary role in our health and wellness, but exercise and consistency make up the ultimate trio.