Ketogenic Diet, Atkins and Paleo

Question 1

Ketogenic Diet

Answer 1

First introduced as a treatment for epilepsy in the 1920s.
* Research shows benefits in a range of health issues.
* Macronutrient ratio is: 75% fat, 20% protein, only 5% carbs.
* The significant reduction in carbs changes the body’s primary fuel source from glucose to fat, putting the body into ketosis
* When glycogen stores are depleted,
glucose levels become insufficient
to support normal fat oxidation.

Question 2

Ketogenic diet and fat

Answer 2

Fat is converted to ketones in the liver and ketones are transported to body tissues, to enter the mitochondria for generation of ATP.
* Ketone bodies (ketones) are able to cross the blood brain barrier to provide an alternate source of energy for the brain.
* Note that ketosis a normal physiologic response is distinct from keto acidosis where ketone bodies exceed levels the body can deal with leading to a decrease in pH seen with poorly controlled diabetes.

Question 3

Keto: Foods to eat

Answer 3

Foods to eat:
* Meat: Red meat, steak, ham,
sausage, bacon, chicken, turkey.
* Fatty fish: Salmon, trout, tuna,
mackerel.
* Eggs, butter, cheese, creams.
* Nuts and seeds: Almonds, walnuts, flax seeds etc.
* Oils, avocados:
* Low carb veggies: Most green
veggies, tomatoes, peppers, etc.

Question 4

Keto: Foods to avoid

Answer 4

Foods to avoid:
* Foods made with flour: Such as bread and pasta.
* Grains: Rice, oats, and quinoa.
* Foods with lots of sugar: Honey, syrup, fruits.
* Starchy vegetables: Potatoes, corn and peas
* Lactose rich dairy products: Milk, ice cream, yoghurts

Question 5

Keto benefits

Answer 5

Epilepsy
Neurological disease
Cancer
Cardiovascular disease
Type II diabetes

Question 6

Keto benefits: Epilepsy

Answer 6

Significant reductions in seizure
number (30-40%) observed in clinical trials.
– It thought that ketone bodies exert anticonvulsant effects and decrease neuronal excitability.

Question 7

Keto benefits: Neurological disease

Answer 7

e.g. Alzheimer’s and Parkinson’s disease. A neuroprotective effect by ketone bodies is proposed relating to:
– Increased ATP production and reduced ROS in nervous tissue.
– Increased synthesis of PUFAs helps stabilise cell membranes.
– An influence on neurotransmitter
activity in neurons.

Question 8

Keto benefits: Cancer

Answer 8

– Thought to change the preferred energy source of some cancer cells, e.g. those expressing insulin and IGF-1 receptors.
– Research has mostly focused on brain tumours.

Question 9

Keto benefits: Cardiovascular disease

Answer 9

– Marked improvements in triglyceride levels.
– increased HDL cholesterol and increased LDL cholesterol
size, which have lower atherogenic potential.

Question 10

Keto benefits: Type II diabetes

Answer 10

– Shown to improve glycaemic control and insulin sensitivity.

Question 11

Keto and weight loss

Answer 11

The ketogenic diet is associated with long term weight management.
Proposed mechanisms include:
* Lack of glucose in the diet leads to a
decrease in insulin, in turn reducing
lipogenesis and increasing lipolysis
* Appetite suppressant effect of ketosis
related to modification of levels of hormones that influence appetite ghrelin and leptin.
* Increased metabolic cost of gluconeogenesis and the thermic effect of protein.

Question 12

Keto disadvantages

Answer 12

• Tachycardia, dehydration, acidosis, hypoglycaemia and constipation (lack of fibre), kidney stones, overacidity, arthritis.
• Key vitamin and mineral deficiencies: Lack of plant based polyphenols and phytonutrients may require supplementation.
• Dyslipidaemia and elevated cholesterol levels: High fat intake
• The quality of dietary fats needs to be considered.
• Long term viability and limitations of
  following a restrictive diet such as keto
  needs to be assessed by the practitioner.
  Long term compliance can be difficult.

Question 13

Atkins Diet

Answer 13

Atkins diet: Low carbohydrate, high protein diet devised by Robert Atkins. Unlimited amounts of protein and fat.
* Mostly recommended for weight loss.
Works on the principles of the ketogenic diet.
* After the initial phase of weight loss, Atkins differs from the KD as more carbs are gradually introduced to determine carb tolerance level that allows maintenance of the individual’s ideal weight.
* Atkins can support weight loss, but is limited in fibre rich foods and encourages excess consumption of animal protein and fats which are linked with health risks such as heart disease and cancer.

Question 14

Paleo Diet

Answer 14

Represents the hunter / gatherer diet from the Paleolithic era (around 2.5 million years ago to 10,000 B.C.):
* Excluded foods: Legumes, grains, dairy products, refined sugar, processed foods.
* Included foods: Fruits, vegetables,
nuts, seeds, meat, fish and plant oils.
* Benefits: Excludes pro inflammatory
dairy products, refined sugar and processed foods which lack nutrients and create health issues.
* Disadvantages: Protein intake,
especially high animal protein. Lack of legumes and grains limits intake of fibre and nutrients.