The Science Behind Low Carb and Ketogenic Diets

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Why We Designed our Weight Loss Program on Evidence not Hearsay

We know research is hard, so we did the work for you. Below you’ll find scientific evidence behind the effects of low-carb and keto diets.

Although these diets have recently become trendy, people have been eating this way all the way back to the caveman days.

Today, there is high-quality evidence to support the benefit of a low carb diet not only for weight loss but also for certain health conditions, such as high blood pressure, type 2 diabetes, and more. 

Science has also suggested that naturally occurring saturated fats are not as harmful as we were first led to believe in regards to health.

Additionally, dangers associated with red meat are based on weak scientific evidence with extreme unlikelihood. As it turns out, low-fat diets do not have more health or weight loss advantages over a low carb diet.

Weight Loss

You’ll see that there has been little scientific evidence in the literature that says any diet is better than another for helping people lose weight. Results show that most people who lose weight on any diet will often regain most or all of it after two years. 

With that being said, studies have shown that diets that restrict carbohydrates often have more success than those that are low-fat.

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The Scientific Literature on Weight Loss

Here are the results of multiple randomized controlled trials, which is considered the most reliable type of tests and all these tests have come to the same results: low carb diets are far superior to other diets when it came to weight loss.

Scientific Study: Comparison of low-carbohydrate and low-fat diets. 

Scientific Study: Effects of low-carbohydrate diets v. low-fat diets on body weight and cardiovascular risk factors

A carbohydrate-restricted diet did not only show that people lost more weight compared to other diets, but also that they had more fat loss.

Scientific Study: Impact of low-carbohydrate diet on body composition

Weight loss and Reduced Risk Factors

This summary of the major low carb diet trials have shown both weight loss and a decrease in major health risk factors for heart disease:

Scientific Study:  Systematic review of clinical trials on the effects of low carbohydrate diets on cardiovascular risk factors 

Low Carb Diet's Randomized Control Trials (RCT)

Many RTC’s have shown higher weight loss with a low carb diet.  How many studies show the opposite of this? None.

Here are three of these Trials:

 

1.  New England Journal of Medicine 2008: Weight loss with a low-carbohydrate, Mediterranean, or low-fat diet

Summary: This was a two-year trial where 322 patients were randomly assigned to follow either a low-fat diet, a Mediterranean diet, or a low-carb diet. By the end of the trial, the low-carb patients had lost more weight, even though they had no restriction on how much low-carb food as they needed to feel satisfied; the other two groups followed calorie-restricted diets.

 

2. Annals of Internal Medicine 2014: Effects of low-carbohydrate and low-fat diets 

Summary: In this one-year trial, 148 people were randomly asked to eat a low-carb diet or a low-fat diet. The low-carb group ended up losing 7.7 lbs more than the low-fat group, and also had greater improvements in high-density lipoprotein cholesterol, triglycerides, and other cardiovascular disease risk factors.

 

3. Journal of the American Medical Association 2007: Comparison of the Atkins, Zone, Ornish, and LEARN diets for change in weight and related risk factors among overweight premenopausal women.

Summary: This popularly known weight-loss trial included randomizing overweight premenopausal females on a low or moderate carb, low fat, low calorie, or portion-controlled diet for one year. The study showed that the low carb women had lost two times the weight of the other groups.

What We Know about Low Carb Diets

All of the studies included on the page show a higher rate of weight loss than the other control groups. From our studies, we have been unable to find any studies saying the opposite of this. This means a low carb or keto diet has never lost a weight-loss trial.

This is why Custom Health Centers has centered their diet around a low carb, high-fat approach to weight loss. The science shows it, and we listened.

Metabolic Risk Factors

Studies show that low carb diets impact the main symptoms of metabolic syndrome: high blood pressure, obesity, low HDL, high TG, and high blood sugar.

Metabolic risk factors have shown to be linked to diseases like heart disease, dementia, stroke, cancer, and type 2 diabetes.

Since low carb diets have shown to help risk factors related to the diseases listed, low carb diets have become an important tool in the prevention of them.

5 contributing factors to weight gain

Summary of Scientific Studies

The results showed us that low carb diets have improved the HDL cholestreol levels in overweight obese adults as well as TG improvements for people who ate low carb or ketogenic with less than 50 grams of carbohydrates a day.

Scientific Study: Effects of carbohydrate-restricted diets on low-density lipoprotein cholesterol levels in overweight and obese adults

Saturated Fats

Are Saturated Fats Bad For You?

Let’s see what science has shown us.

Regardless of years of research, there still has not been any evidence that suggests  natural occurring saturated fats like grass-fed butters and eggs are bad for your health.

The top leading researchers in this field have come to the conclusion that it is wrong to continue to spread non-factual advice to reduce saturated fat intake. 

Scientific Studies into Saturated Fats

Scientific Study #1: Archives of Internal Medicine 2009: A systematic review of the evidence supporting a causal link between dietary factors and coronary heart disease 

Summary: This 2009 systematic study looked at potential relationships between dietary choices and heart disease showed that “Insufficient evidence of association is present for the intake of … saturated or polyunsaturated fatty acids; total fat … meat, eggs and milk”

Scientific Study #2: The American Journal of Clinical Nutrition 2010: Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease

Summary: A 2010 trial found “…no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD”

We looked at two reviews of randomized controlled trials, there is still no strong evidence that saturated fat has a negative effect on your health. Instead, we found that research concluded that replacing saturated fats with unsaturated fats may actually reduce the risk of heart attack by 14 to 19 percent.

Scientific Study #3: European Journal of Nutrition 2012: The relationship between high-fat dairy consumption and obesity, cardiovascular, and metabolic disease

Scientists studied the difference between a diet of full-fat dairy and patients heart health and weight and concluded that “the observational evidence does not support the hypothesis that dairy fat or high-fat dairy foods contribute to obesity or cardiometabolic risk”

The scientific studies in which we have listed indicate that dietary advice to avoid fats and saturated fat is based on an extremely weak scientific foundation. 

Type 2 Diabetes

The health benefits of switching to a low carb diet for people who suffer from type 2 diabetes has been widely accepted by many researchers.

 

A research trial in 2017 found that a low-carb diet had the effect of improved health markers (TG, HbA1c, HDL, and blood pressure) and decreased need for medication. These scientists came to the conclusion that: “Reducing dietary carbohydrate may produce improvements when managing type 2 diabetes”

Scientific Study: European Journal of Clinical Nutrition 2017: The interpretation and effect of a low-carbohydrate diet in the management of type 2 diabetes

 

This study not only claimed that low-carb diets help in the treatment of type 2 diabetes, but they also suggest that the first approach to managing type 2 diabetes is by changing to a low carb diet. 

Scientific Study Nutrition 2015: Dietary carbohydrate restriction as the first approach in diabetes management

Type 1 Diabetes

In comparison to the plethora of evidence supporting low carb and ketogenic diets to treat type 2 diabetes, trials for type 1 is lacking. Regardless, the studies we do have show encouraging results for managing type 1 diabetes with a low-carbohydrate diet.

These studies below have shown that people with type 1 diabetes who limit carbs to 50 to 100 grams per day experience less frequent episodes of hypoglycemia and more balance blood sugar when compared to type 1 diabetes patients who eat high-carb diets. We also see increased weight loss for type 1 patients who are overweight. Here are the studies:

 

  1. Diabetes, Obesity and Metabolism 2019: Low versus high carbohydrate diet in type 1 diabetes
  2. Diabetes, Obesity and Metabolism 2017: Short-term effects of a low-carbohydrate diet on glycaemic variables and cardiovascular risk markers in patients with type 1 diabetes
  3. Asia Pacific Journal of Clinical Nutrition 2016: A randomised trial of the feasibility of a low-carbohydrate diet vs standard carbohydrate counting in adults with type 1 diabetes taking body weight into account

 

Epilepsy

Low Carbohydrate and Ketogenic diets have been frequently studied in cases of epilepsy. The ketogenic diet was originally founded in science to help prevent seizures in epileptic patients. When patients are not responding to anti-seizure medication or cannot handle side effects, doctors will often place the patient on a low carbohydrate diet. 

A large study in adults with uncontrolled epilepsy found that low carb and ketogenic diets were helpful in controlling seizures long term and in a few cases, the patient gained freedom from seizures completely!

Scientific Study: Epilepsia Open 2018: Ketogenic diet for treatment of intractable epilepsy in adults

 

Studies have come to a fairly solid conclusion that ketogenic diets are extremely effective for seizure control in many children and adults who suffer from epilepsy.

  1. Epilepsia 2018: Effect of modified Atkins diet in adults with drug-resistant focal epilepsy: a randomized controlled trial 
  2. Acta Neurologica Scandinavica 2017: A randomized controlled trial of the ketogenic diet in refracatory childhood epilepsy 
  3. Epilepsy Research 2016: Evaluation of a simplified modified Atkins diet for use by parents with low levels of literacy in children with refractory epilepsy: a randomized controlled trial

Liver Disease

Did you know that a low carb diet has shown in some studies to help reverse fatty liver disease?

In 2019 a team of scientists published a journal Cell Metabolism that showed evidence of the effects of low-carb diets with obese patients with fatty liver disease. These patients did not reduce any caloric consumption and found dramatic reductions of liver fat and risk factors. 

Scientific Study: Cell Metabolism 2017: An integrated understanding of the rapid metabolic benefits of a carbohydrate-restricted diet on hepatic steatosis in humans

Irritable Bowl Syndrome

A scientific study into extreme carbohydrate restriction for treating irritable bowel syndrome (IBS) showed that patients had improvements in reducing abdominal pains and frequent diarrhea. 

Scientific Study: Clinical Gastroenterology and Hepatology 2009: A very low-carbohydrate diet improves symptoms and quality of life in diarrhea-predominant irritable bowel syndrome

Scientific Study: European Journal of Nutrition 2016: Does a diet low in FODMAPs reduce symptoms associated with functional gastrointestinal disorders?