Here is a collection of research articles regarding nutrition, health, obesity, and low-carb high-fat diets from peer-reviewed scientific journals, grouped by topic. For each article, I’ve included a short summary of the study’s main finding along with a link to the original paper.
These studies show that a diet low in carbohydrates and high in fat (or “LCHF,” like the ketogenic diet) is healthy with many benefits, leading to weight loss and cardiovascular benefits. This is in contrast to what many people unfortunately still believe — the incorrect assumption that eating fat makes you fat, despite extensive research attempting and failing to establish a relationship between fat consumption and obesity.
The emphasis on dietary fat reduction from public health officials and so-called health experts has been a very unfortunate distraction with serious consequences in efforts to control obesity and improve health in general.
The current obesity and health epidemic is due not only to diet but also to increased meal frequency and constant snacking. Accordingly, I have included several articles below regarding the health benefits of fasting. Intermittent fasting is an effective way to control insulin resistance and to lose weight.
Lastly, I’ve included some studies regarding low carb foods that are notable for their health benefits, including vinegar, chocolate, coffee, tea, and cinnamon. Many people ask about the healthiest sugar-free sweetener to use, so I have included research regarding my sweetener of choice, erythritol.
- The benefits of low-carb high-fat diets
- The harmful effects of carbs (sugar), especially soft drinks
- Eating more carbs such as grains, fruits, and vegetables doesn’t make you healthier
- Why more frequent eating isn’t good for you
- Benefits of short and long term fasting
- Benefits of vinegar, chocolate, nuts, coffee, & cinnamon
- Why erythritol is the best sweetener to use
The benefits of low-carb high-fat diets
- Severely obese people have greater weight loss while on a low carb diet compared to a calorie-restricted, low-fat diet. While on a low carb diet, subjects improved in glycemic control, had no adverse effects on blood lipid levels, and had lowered triglyceride levels which is indicative of a cardiovascular benefit.
- A 2-year study of obese women shows that the low carb diet is more effective in weight loss compared to both the mediterranean diet and low fat diet.
- Weight gain after weight loss is thought to be due to decreased energy expenditure. Lowering carbohydrate intake increased energy expenditure during weight loss maintenance, which may increase the chances of successful obesity treatment.
- In a 2-year study of Type 2 diabetics, participants selected either a low carb diet (initially <30 g total carbs daily) or standard diabetes care. In the group with the low carb diet, half of them reversed their diabetes. The group with standard care did not experience diabetes reversal or improvement, and some participants worsened.
- Obese patients with type 2 diabetes were given a low carb diet and after 14 days, patients had significantly improved blood glucose profiles and insulin sensitivity as well as decrease triglyceride and cholesterol levels.
- Patients were treated with a low fat or low carb diet for 2 years. The low carb patients had more favorable changes in cardiovascular disease risk factors.
- From a review of 16 studies covering the relationship between dairy fat consumption, obesity, and heart disease, they found no evidence that dairy fat contributes to obesity or cardiometabolic risk. In fact, these studies suggest that high fat dairy consumption is inversely associated with obesity risk.
- A study of over 800 middle-aged men during 20 years of followup shows that dietary intake of fat, saturated fat, and monounsaturated fat are associated with lower risk of stroke.
- Obese patients were subjected to a 24-week ketogenic diet. After the study, patients had significantly decreased weight and body mass index, decreased total cholesterol, increased HDL cholesterol, decreased LDL cholesterol, decreased triglycerides, and decreased blood glucose. There were no significant side effects.
- Obese participants diagnosed with metabolic syndrome (linked to cardiovascular risk like heart disease and stroke) were given low/med/high carb diets. After 4 weeks, a low carb diet was found to be most effective at reversing metabolic syndrome, compared to moderate and high carb diets.
- Nearly 150 men and women without cardiovascular disease or diabetes participated in either a low-fat or low-carb diet. The low carb diet was more effective for weight loss and cardiovascular risk factor reduction than the low fat diet.
- Subjects following a low carb ketogenic diet and CrossFit training saw decreases in their body fat percentage, fat mass, and BMI while maintaining their lean body mass. They also had improvements in their performance power and time.
- From a study of 30 adults over 10 weeks, a keto diet with no exercise out-performs a standard American diet with exercise in terms of weight, body fat percentage, BMI, and hemoglobin A1c.
- Cheese contains a high level of saturated fatty acids, so an analysis was performed to determine how long-term cheese consumption affected cardiovascular disease. This analysis was based off of 15 studies that showed higher cheese consumption is associated with a lower risk of cardiovascular disease.
- Autistic children received either a keto diet, a gluten-free dairy-free diet, or a balanced nutrition diet (control group). After 6 months, both diet groups showed significant improvement in autism rating scales and evaluation tests, with the keto group scoring even better in cognition and sociability compared to the gluten-free dairy-free group.
The harmful effects of carbs (sugar), especially soft drinks
- Sugary beverages are linked to weight gain and increase in type 2 diabetes in women.
- By studying food and diabetes prevalence in 175 countries, it was found that for every 150 kcal/person/day increase in sugar availability (about 1 can of soda each day), it was associated with an increase in diabetes prevalence of about 1%.
- Daily consumption of diet soft drinks are linked to an increased risk for stroke and other vascular events.
- Among middle aged adults, soft drink consumption is associated with higher incidence of cardiometabolic risk factors.
- From a study of relationships between nutritional factors and the prevalence of cardiovascular diseases in Europe, the major correlate of high cardiovascular disease risk was the proportion of dietary energy from carbs and alcohol, or potatoes and cereal carbs. Even unrefined cereals have high insulin indices.
- The sugar industry secretly funded a study in 1965 to evaluate sugar’s effect on cardiovascular health. When the results suggested that sugar was harmful, they buried the data.
- Analysis of the Alaskan Inuit diet shows that higher consumption of carbs and sugar is linked to the rise of coronary heart disease and diabetes.
- From a study with 12 years of follow up, results suggest that high carb consumption increases the risk of gall stone disease in men.
- A double-blind, placebo-controlled study of 49 people shows that consuming sucrose (sugar) and glucose leads to poorer performance on cognitive tasks such as simple response time and arithmetic.
- From a study of 5189 subjects over 10 years, people with high blood sugar have a faster rate of cognitive decline including dementia than those with normal blood sugar, regardless if they are diabetic or not. The higher the blood sugar, the faster the cognitive decline.
Eating more carbs such as grains, fruits, and vegetables doesn’t make you healthier
- Health experts often recommend eating more fruits and vegetables to lose weight. A review of two studies showed that increased fruit and vegetable consumption does not cause weight loss.
- A study of nearly 50,000 women over 8 years showed that a diet low in fat and high in vegetables, fruits, and grains did not reduce the risk of cardiovascular disease, stroke, and coronary heart disease.
Why more frequent eating isn’t good for you
- Increasing meal frequency does not help promote greater weight loss.
- In a study of obese men, satiety and fullness-related responses were greater on a higher protein diet but lower when they increased their eating frequency. This challenges the idea that increasing the number of eating occasions increases satiety.
- High meal frequency increases abdominal fat, but increasing meal size does not, which is why frequent snacking leads to obesity.
Benefits of short and long term fasting
- A 27-year-old 456-pound man fasted for 382 days under doctor supervision, losing 276 pounds or 0.72 pounds/day, with no ill effects.
- Fasting affects circadian clocks in the liver and skeletal muscle, which impacts their metabolism. This can lead to improved protection against aging-related diseases.
- Short term fasts (24-48 hours) produce a therapeutic neuronal response in the brain.
- Analyzing young adults who fast during the month of Ramadan, their blood lipoprotein metabolism improved with an increase of HDL cholesterol. This increase was lost after Ramadan.
- Obese subjects were studied over 10 weeks with an alternate-day fasting diet. At the end of the trial, their fat mass decreased, their LDL cholesterol was 25% lower, and their waist circumference was reduced.
- A study of healthy men and women on a 36 hour fast did not lead to a stimulus to compensate after the fast.
Benefits of vinegar, chocolate, nuts, coffee, & cinnamon
- Drinking 2 tablespoons of apple cider vinegar at bedtime moderates the next morning’s fasting glucose concentration for those with type 2 diabetes.
- Consumption of dark chocolate decreases blood pressure, insulin resistance, and may provide some cardiovascular benefits.
- Dark chocolate consumption is inversely related to coronary heart disease in the U.S. population.
- Examining data from large epidemiological studies across two continents, an 8% reduction in risk of death from coronary heart disease was found for each weekly serving of nuts. Intake of nuts lowers total and LDL cholesterol.
- High intakes of coffee, decaf coffee, and tea are linked to lower risk of diabetes.
- Coffee and tea consumption is associated with a reduced risk of type 2 diabetes, which cannot be explained by magnesium, potassium, caffeine, or blood pressure effects.
- A study of healthy men shows that decaf coffee decreases hunger and increases the satiety hormone.
- Cinnamon consumption reduces blood glucose but has no significant effect on satiety.
- Human fat cells exposed to cinnamaldehyde, a compound in cinnamon, undergo thermogenesis, a process where the cells burn fat for energy.
Why erythritol is the best sweetener to use
- Erythritol does not affect blood levels of glucose or insulin. More than 90% of the ingested erythritol is readily absorbed and excreted in the urine.
- Erythritol is a promising sugar substitute from a dental point of view, as researchers found that it resulted in significantly less dental decay compared to sucrose (table sugar).
- Erythritol causes significantly less intestinal distress than xylitol.
- An overweight adolescent is significantly more likely to have an increased risk of mortality from all causes and diseases, no matter the adult weight after 55 years of follow-up. In particular, colorectal cancer and gout among men, arthritis among women, and coronary heart disease among both groups. Being overweight in adolescence is a more accurate predictor of these risks than being overweight as an adult.
- Nearly half of all incident cancers and cancer deaths in 2014 were due to unhealthy and preventable behavior: cigarette smoking (29% cancer deaths), excess body weight (7%), and alcohol intake (4%).
- Egg consumption does not lead to higher risk of developing coronary heart disease, but in fact has multiple beneficial effects.
- A low carb diet over 2 years is not linked to harmful effects related to kidney functions.
- In a study including nearly 30,000 people over 5 years, those who ate more than 30% of their daily diet in fat did not have increased mortality, so dietary recommendations regarding fat intake are not supported by these results.
- Both glucose and fructose consumption contribute to weight gain, but fructose causes significantly higher cholesterol concentrations and reduces sensitivity to insulin.
- Young healthy subjects were fed usual diets plus either glucose or fructose. After one week, the group with fructose feeding had a significant reduction in their insulin binding and insulin sensitivity, whereas the glucose group had no significant change. Fructose rather than glucose is responsible for the insulin binding/sensitivity issue in sucrose.
- From a study of over 90,000 women over 8 years, higher glycemic index foods are associated with an increased risk of diabetes, but fiber intake is associated with a decreased risk.
- Thirteen patients with type 2 diabetes followed either a moderate fiber diet (24 g) or a high fiber diet (50 g). Both diets were prepared in a research kitchen with the same macro and energy content. The patients on the high fiber diet had reduced total cholesterol concentrations by 6.7%, triglyceride concentrations by 10.2%, and lipoprotein cholesterol concentrations by 12.5%.
- From a study of 245 Finnish men at age 63, male pattern baldness was found to be common, but associated with insulin resistance related issues such as diabetes and hypertension. Rate of diabetes was almost twice as much in men with hair loss.
- From a study of 324 women at age 63, those with hair loss had significantly higher insulin resistance related parameters like waist/neck circumferences, waist-to-hip ratio, and insulin concentration compared to those with normal hair or very minimal hair loss.