…said another YouTube influencer.
Meanwhile, scientific research shows that carbohydrates themselves neither stop nor slow down weight reduction.
Rice Diet – average weight loss of 64kg.
Historical Curiosity.
In 1939, Dr. Walter Kempner developed the so-called rice diet to see if an extremely low-protein and low-fat diet could improve the condition of patients with hypertension.
It is worth remembering that effective medications for hypertension only became available after 1958.
Diet composition:
- white rice
- fruits
- fruit juices
- sugar (if calorie intake needed to be increased)
Almost all carbohydrates, with minimal fat and protein.
Calories:
- patients with hypertension only: approx. 2000 kcal
- obese patients: 800–1000 kcal
Effects:
- average weight loss: approx. 23 kg in 100 days (from ~103 kg to ~80 kg)
- in a 1975 publication, Dr. Kempner described the results of using this diet specifically for weight loss in very obese patients – 106 people participated
- minimum weight loss: ~45 kg
- average weight loss: ~64 kg
Important clarification:
Of course, I am not suggesting that anyone eat only carbohydrates, but this is strong evidence that calorie restriction causes weight loss, not a magic diet or magic hours when we eat meals.
The rice diet probably resulted in significant muscle mass loss due to lack of protein and strength training.
This is just a curiosity for those looking for a shortcut. Unfortunately, you have to cut calories.
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The biggest advantage of carbohydrates is more energy if you exercise.
I personally tried diets:
- keto
- keto with carb refeeds once a week
- 3 months on Carnivore (meat only)
- carb cycling
- balanced
I train kickboxing (2x a week) + gym (1, max 2x a week).
For me, carb cycling or simply extra carbohydrates before and after training definitely work best. Workouts suffer the least then.
In any case, the best diet is the one you will stick to. This post is not to promote carbohydrates, but to make people aware that calories determine weight reduction, and protein + strength training + slow calorie reduction (weight loss at a rate of 0.5%-1% per week) allow you to maintain muscle mass. Whether the rest of the calories come mainly from fats or carbohydrates does not matter for weight loss itself, but it may matter for maintaining training intensity.
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The Carbohydrate-Insulin Model (CIM)
The Carbohydrate-Insulin Model of Obesity
Hypothesis:
Since insulin is secreted after carbohydrate consumption, and insulin promotes energy storage in fat tissue, carbohydrates may hinder weight loss.
And… that’s pretty much it. This was a hypothesis that was subsequently repeatedly tested in clinical trials — and its key assumptions were not confirmed.
Why does this model sound credible?
The carbohydrate-insulin model is based on a real physiological phenomenon, which makes it intuitively convincing.
Short-term mechanism ≠ long-term effect
For some reason, this gets lost in online arguments.
Insulin inhibits lipolysis (fat burning) after a meal, but:
- it doesn’t do it permanently
- its effect is temporary
- fat burning increases between meals and at night
The body functions cyclically; after eating, it stores energy, and between meals, it releases it.
The sum of these processes over the day and week determines weight reduction or gain, not a temporary insulin spike after eating rice or potatoes.
Hunger and “insulin spikes”?
After the main assumptions of CIM are debunked, a substitute argument often appears:
“OK, maybe carbohydrates don’t block fat burning, but they cause insulin spikes and hunger pangs.”
Studies on hunger favor high-carbohydrate diets; personally, on keto, I felt less hungry than on low-fat diets, but that’s just my perception.
High-Carbohydrate vs. Ketogenic Diet
Hall KD et al., Nature Medicine, 2021
Participants were divided into two groups (keto vs. carbs) and allowed to eat as much as they wanted to see if the eating pattern would affect the amount of calories consumed if people weren’t monitoring themselves.
People on the carbohydrate diet ate 500-700 kcal less than those on the keto diet.
In this study, the carbohydrate diet (75% carbs, 10% fat) was based on vegetables, fruits, whole grains, and a high amount of fiber, not pasta and cookies.
When we think of a carbohydrate diet, we tend to (at least I do) picture pasta, rice, etc.
The keto group (75% fat, 10% carbs) ate meat, eggs, fish, dairy, and added fats (butter, oils).
Hall KD et al., 2016 (Metabolic Chamber Study)
Equal calories and protein – balanced diet vs. keto.
- Participants: 17 overweight or obese men.
- Protocol: For the first 4 weeks, they ate a balanced diet (50% carbohydrates, 35% fats, 15% protein), and for the next 4 weeks, a ketogenic diet (5% carbohydrates, 80% fats, 15% protein).
- Key details:
- Calories: The same amount in both phases, slight deficit.
- Insulin: After switching to keto, insulin levels dropped by 47%. According to CIM theory, fat should have started to “melt away” before their eyes.
- Result: The rate of fat loss did not change; ultimately, the difference in fat loss between the diets was minimal.
A drastic drop in insulin did not cause magical changes.
DIETFITS (Gardner et al., 2018)
This study aimed to determine whether we should tailor our diet to our genes or insulin levels.
- Participants: 609 people (women and men).
- Co jedli?
- High-Fat, Low-Carb Diet (HLF): Whole-grain products (brown rice, oats), lean meat, low-fat dairy, plenty of legumes and fruits.
- High-Carb, Low-Fat Diet (HLC): Olive oil, avocado, fatty fish, meat, nuts, cheese, and low-starch vegetables.
- Common denominator: Both groups were to limit added sugars and refined grains (white flour) as much as possible and eat as many vegetables as possible.
- Calories?: They ate as much as they wanted, in a sense, but only until satiated. Participants were taught self-control, slowly adding ingredients so that people with bad habits wouldn’t pour 1000 kcal of olive oil into a salad, etc. Ultimately, both groups had a deficit of about 500 kcal.
- Notes:
- Before the study, participants were genetically tested and their insulin secretion was measured after glucose administration.
- The hypothesis tested was: “People with high insulin (insulin resistant) will lose weight better on low carbohydrates.”
- Result: After 12 months, both groups lost roughly the same amount of weight on average (~5.5-6 kg). Insulin levels and genotype had no impact on how much weight anyone lost.
- Conclusion: If the diet is based on unprocessed foods, your “insulin status” does not determine whether you will lose weight on carbohydrates or fats.
Meta-analysis by Hu et al., 2012
Analysis of 23 clinical trials (RCTs).
- Scope: Data from 2178 people were collected
- What was analyzed? Low-carbohydrate and low-fat diets were compared.
- Results
- Both dietary approaches improved blood pressure, fasting blood sugar, and waist circumference.
- Lipid profile: Low-carbohydrate diets typically raised HDL cholesterol more and lowered triglycerides, while low-fat diets lowered LDL cholesterol more.
- Weight loss was practically the same.
In summary, it doesn’t matter whether your diet consists mainly of protein and fats or protein and carbohydrates; you can eat in a way that suits you better.
You will lose weight if calories are restricted.
