Keto Diet Evidence and Ketogenesis Basics

Keto Diet - Evidence

• Ketogenic diets reduce refined sugar intake and increase protein and fat.
• The purpose is to increase ketogenesis (fatty acid oxidation in the liver).
• Americans consume roughly half their daily calories from carbohydrates, with 80% coming from added sugars and refined grains (soda, candy, bagels, pastries, and pizza crust).
• The Mediterranean diet is a lifestyle, not just a diet, and has significant health benefits.
• Numerous studies investigate different nutritional interventions, including ketogenic diets (KD) and very-low-calorie ketogenic diets (VLCKD). These diets are medical nutrition therapies for diabetes and obesity.

Ketogenesis & Ketoacidosis

• Low carbohydrate stores/high fatty acid concentration upregulate the ketogenic pathway, increasing ketone body production.
• Ketoacidosis occurs when too many ketone bodies accumulate, potentially in uncontrolled diabetes.
• Activation of adipose tissue lipolysis (fat breakdown) promotes ketogenesis in the liver via PPARalpha.
• Most organs use ketone bodies for energy, but the brain relies on them during glucose shortages.

Ketone Production

• Fed State: Dietary glucose and fats are used for energy. Insulin promotes glucose storage.
• Fasting State: Decreased insulin; increased glucagon; fat breakdown (lipolysis); increased ketones in bloodstream.

Cholesterol Biosynthesis Regulation

• HMG-CoA reductase is a rate-limiting enzyme in cholesterol biosynthesis, targeted by statin drugs.
• HMGCR converts HMG-CoA to mevalonic acid.
• Normally, HMG-CoA reductase is suppressed in cells to regulate cholesterol production.
• Insulin activates, while glucagon and oxysterols inhibit the enzyme.
• Oxysterols, cholesterol derivatives, accumulate with excess cholesterol, blocking LDL receptor-mediated endocytosis.
• Low cellular energy (decreased ATP) activates AMPK, which inhibits HMG-CoA reductase.

Italian Ketogenic Mediterranean Diet

• This study investigated the Italian Ketogenic Mediterranean Diet (VLCKD-MED) in overweight/obese patients with prediabetes or type 2 diabetes.

Baseline Patient Characteristics

• Study participants were a mix of men and women.
• Participants' ages, weights, heights, and BMIs were similar across groups.

VLCKD-MED Food List

• Includes ample quantities of leafy green vegetables, and limited quantities of specific vegetables.
• Includes various fruits, nuts, and other foods.

VLCKD-MED Composition

• Diet composition includes specifics on calorie distribution among fats, proteins, and carbohydrates.

Mediterranean Diet Serving Score

• This table details recommended servings (vegetables, olive oil, nuts, eggs, fish, white meat, and red wine).

Demographic, Anthropometric, and Body Composition Variables

• Detailed data on age, BMI, weight, height, waist/hip circumference, fat/free fat mass, etc. are presented and categorized by treatment group (VLCKD-MED and VLCD-MED).

Blood Chemistry Variable Changes

• Measures the effects of each treatment regimen on blood sugar, insulin, and other key blood components.
• Includes a detailed table with various blood parameters and their changes pre- and post-intervention.

PCOS - Polycystic Ovary Syndrome

• PCOS is the most common female endocrine disorder impacting reproductive-aged women.
• Characterized by phenotypic and metabolic complications.
• Insulin resistance (IR) is a prominent factor, often related to obesity and abdominal fat distribution.
• PCOS presents with symptoms like irregular periods, excessive hair growth, acne, and fertility concerns.

PCOS, Overweight/Obesity, and Metabolic Factors

• Overweight or obesity is common in women with PCOS, impacting insulin resistance and hormonal imbalances.

Ketogenic Diet in PCOS (Background)

• The ketogenic diet (KD) limits carbohydrate intake to reduce blood glucose and insulin.
• While evidence is limited, a pilot study explored the effects of a very-low-calorie ketogenic diet (VLCKD) on overweight/obese women with PCOS.

Dietary Treatment Protocol

• Study groups (overweight/obese women) followed either a modified ketogenic diet (VLCKD-MED) or a balanced, hypocaloric Mediterranean diet (MD). The durations and daily allowances are specified.

Ketogenic, Mediterranean Diet Details

• The ketogenic diet specifications are outlined.
• Multivitamin and mineral supplementation and dietary components are noted; details on olive oil use are given.

Exclusion Criteria

• Detailed exclusion criteria for the study groups are outlined; these involve age, menopause, pregnancy, specific diseases, and use of some medications.