Ketogenic Diet for Athletes
This is a summary of the salient points of the book “The Art and Science of Low Carbohydrate Performance”, by Jeff S. Volek and Stephen D. Phinney.
- A high carbohydrate diet locks a person into a dependence on carbohydrate as the dominant fuel for exercise (page 2)
- You can train your body to burn fat by simply changing your diet (page 2)
- After a few weeks you can train harder, perform longer, and recover fast. (page 2)
- Low carbohydrate diets are anti-inflammatory (page 4)
- produces less oxidative stress during exercise (page 4)
- more rapid recovery between exercise sessions (page 4)
- much less dependence on muscle glycogen (page 4)
- less need to reload with carbohydrates during and after exercise (page 4)
- low carb adaptions accelerates the use of saturated fats of fuel, allowing a high intake of total fats (including saturates) without risk (page 4)
- By reducing oxidative stress and inflammation, gut and immune functions are better maintained (page 44)
- With the advent of agriculture, the average height of the population decreased by 6 inches, and average longevity declined by 10 years.#
Human Body composition
- 400-500 grams of glycogen in your body (1600-2000 kcal) (page 10)
- practically unlimited fat, e.g. 10kg when you are very lean (90.000 kcal) (page 10)
- In well trained athletes, muscles cells can store as much energy in fat droplets as they can store as glycogen (page 14)
- Drink 1-2 cups (250-500ml) of water 5 minutes before exercise (page 83)
- Low Carb + Resistance Training is great. From the study “Low carbohydrate diets promote a more favorable body composition than low fat diets”, 2010 (page 26):
- -2% bodyfat: Low Fat group
- -3.4% bodyfat: Low Carb group
- -3.5% bodyfat: Low Fat + Resistance Training
- -5.3% bodyfat: Low Carb + Resistance Training
- Exercise sharply increases production of oxygen free radicals (ROS), which attack HUFA’s# in cell membranes. (page 32)
- low muscle HUFA is related to insulin resistance. (page 32)
- Protein-Sparing: When keto-adapted, the body improves its efficiency of protein utilization (page 32, 33, 34)
- BOHB Ketones are associated with better maintenance and increase in BCAA# which are essential proteins, because ketones can be burned in place of BCAA (page 33)
- Less central fatigue when keto-adapted (page 34)
- Less accumulation of lactate when keto-adapted (page 34)
- Respiratory quotient (RQ)# at most workouts is lower, so it is easier to breath (page 35)
- Cardio seems to slow metabolism by 5% to 15% which means it could make weight loss slower! (page 41)
- Post Exercise carbohydrates are a bad idea when keto-adapted (page 61)
- Glycogen usage during exercise is dramatically reduced anyways
- Post exercise carbs rapidly decrease the release of fatty acids and oxidation of fat in the muscle (page 61)
- carbs diminishes the beneficial effects on insulin sensitivity and other cardio-metabolic risk markers (page 61)
- insulin has anabolic effects by increasing amino acid uptake and protein synthesis, but only a small amount of insulin is necessary to achieve a maximal effect (page 57)
- When you weight the trivial benefit of insulin stimulating carbs on protein balance vs. potent negative effect on fat breakdown, limiting carbs seem the better choice. (page 58)
- Post workout Protein is a good idea (in moderation) (page 67)
- Protein balance is negative after exercise if amino acids are not provided before, during or after exercise
- Primary driver of muscle protein synthesis is not insulin, but availabilty of essential amino acids, especially leucine#.
- Replace water and sodium loss after a workout.
- The liver maintains blood glucose levels (page 11)
- It takes weeks to become an efficient fat burner (keto-adaptation) (page 11)
- Maximum fat oxidation: Fat usage has an optimal VO2max point. When you train too hard your body cannot use fat for fuel.
- Normal diet: maximum fat oxidation is around 65% of VO2max when trained. 10-60 grams fat per hour, depends highly on the individual. (page 16)
- Keto diet: 70 – 110 grams of fat per hour, 50% greater fat usage! (page 23)
- Equal or better endurance after 2-4 weeks adaptation (page 20, 22)
- First few days of keto adapation
- increased use of both ketones plus fatty acids (adipose, intra-muscular triglycerides, LDL in skeletal muscless (page 25)
- After a few weeks
- muscles rely heavily on fatty acids, muscles adapt away from ketones to spare ketones (page 25, 30)
Fat Energy Cycle
- Dietary fat is absorbed and packed as triglycerides into a blood borne particle called chylomicron# (page 14).
- Fatty acid-releasing enzymes (lipoprotein lipase) perfuse muscle and fat cells, and act upon the chylomicron. (page 14).
- Fatty acids released from chylomicrons can be taken up by nearby muscles or fat cells.
- Fat breakdown (=lipolysis) starts by removing the fatty acid from the glycerol backbone (breakdown of triglyceride#) (page 12)
- Fat breakdown is controlled by insulin: it inhibits the breakdown activity. (page 12)
- fat breakdown is inversely proportional to insulin concentration (page 12)
- Insulin’s effect on fat breakdown is virtually immediate. (page 13)
- Keto-adaptation is not immediate: it takes 2-3 weeks of consistently restricting carbs. (page 13)
- Fatty acids are attached to the protein albumin and delivered to muscle. (page 13)
- Fat is transported into the muscles to ATP generators called mitochondria# (page 13)
- Adenosine tri-phosphate (ATP) is the bodies energy fuel used by muscles. (page 9)
- ATP demands increase several-fold when exercising vigorously (page 9)
- ATP cannot be stored: it is rapidly built from other energy sources, carbs and fat. (page 9)
- When at rest, the fatty acid is converted back to triglyceride within the muscles and stored as lipid droplets for later use. (page 13).
- Ketones Beta-hydroxybutyrate (BOHB) and Acetoacetate (AcAc) are made in the liver from fatty acids. (page 21)
- Blood ketone levels of BOHB to AcAc levels are usually 4:1. (page 90)
- Resting levels of BOHB are usually below 0.2 millimolar when consuming >100g carbs a day, and between 1.5 and 2.5 millimolar <50g carbs a day. (page 90)
- Optimal fuel flow for brain and muscle is between 0.5 and 3.0 millimolar BOHB in the blood. (page 91)
- Ketones are water soluble, so easy to transport in the blood. (page 21)
- Ketone are produced in the liver, and increases in response to decreased carbohydrate availability and increased fatty acid delivery (page 21, 25)
- Ketones are transported to muscles and brain (page 21)
- Inverse relationship in muscles (page 30)
- low blood ketone levels means high muscle uptake
- high blood ketone levels mean low muscle uptake
- Direct relationship in brain: High ketones, high uptake. (via monocarboxylic acid transporters#) (page 30)
- Anectotally, ketones improve cognition during and after exercise (page 31)
- Besides fuel, ketones provide substrates to help repair damaged neurons (page 31)
- Ketones are like a clean-burning fuel: decrease ROS production, increase antioxidant defenses (page 44)
- Urine strips (Ketostix) change color in proportion to the level of AcAc and acetone. This test has been found to inaccurately reflect actual blood ketone concentrations in several studies#. Urine ketones may decrease even as blood values stay in desirable range. (page 91)
- Blood tests are more definitive, but expensive. It’s the way to go when you want to be sure you are reaping the benefits. (page 92)
- Breath tests are better than urine tests, and will be commercially available soon. (page 92)
- Factors impacting Ketone Production (page 93)
- Carbs. <50g is a good target for most people to stay above 0.5 millimolar of blood ketones. Some individuals need to stay below 30 grams, some can have 100 grams. (page 93)
- Protein. Over half of the amino acids are converted to glucose in the body, producing an anti-ketogenic effect. (page 93)
- Exercise. Ketones increase sharply during the 1-2 hours after exercise due to increased hepatic delivery of fatty acids and greater fat oxidation. This will be completely blunted if high amounts of alanine# are ingested. Avoid it. (page 94)
- Time of day. Lowest levels are observed in the morning, levels gradually increase by 25% to mid afternoon, and more rapid increases after meals low in carbs and high in fat.
- Medium Chain Triglycerides (MCT)#. MCT are shorter than most fats we eat.
- They are absorbed much more quickly (page 94)
- don’t get stored in fat cells – they need to be processed immediatly (page 94)
- MCTs are promptly oxidized in muscle cells or used by the liver to make ketones. (page 94)
- Source are butter (10-15% of the fat),, cream, coconut oil (75% of the fat) (page 94)
- Ingestion of MCT oil will result in significant ketosis even if consumed with carbs, although this MCT-induced ketone production may not be associated with the full spectrum of metabolic benefits associated with carbohydrate-restricted keto adaption. Thus, we do not encourage use of MCT oil. (page 95)
What to Eat
- Stay below 50 grams of carbs (page 54)
- Protein (5-10 grams carbs/day) (page 56, 57)
- Avoid highly processed proteins: processing deletes much of the protein, potassium, magnesium
- Whole eggs, hard cheese or cream cheese, use cream (Schlagobers) in place of milk, plain greek yoghurt, …
- Total carbs in yoghurt may seem high, but much of this was converted to lactic acid# which does not raise insulin or interfere with ketosis
- Vegetables (10-15 grams carbs/day) (page 58)
- Enjoy at every meal. Avoid starchy ones like potatoes, yams, sweet potatoes, corn, carrots, beets, dried beans, peas.
- common ones include: Asparagus, Broccoli, Celery, Cucumber, Cauliflower, Chard, Collards, Eggplant, Endive, Green beans, Kale, Mushrooms, Mustard green, Lettuce (all varieties), Onions, Pea pods (snow and snap varieties), Peppers, Radish, Spinach, Summer squash (zucchini and crookneck)
- Nuts and Seeds (5-^10 grams carbs/day) (page 59)
- limit yourself to 2 ounces (56 grams) per day.
- Fruits (5-10 grams carb/day) (page 59)
- up to 3.5 oz (100 grams) per day.
- Berries, tomatoes, olives, avocados
- Avoid juice
- Stay in the range of 0.6 to 1 grams per pound lean body mass. (1.3 to 2.2 grams per kg lean body mass.
- For 75kg, 12% bodyfat: 75*(1-0.12) * 1.3 = 86 grams to 145 grams
- Post workout:
- Eat a good source of essential amino acids after exercise to increase muscle mass: consider a fruit smoothie from naturally fermented yoghurt, home-made meat broth, creamed soups with broth.
- Fat is your friend. Its the predominant fuel during rest and exercise. (page 69)
- Carbs and protein are locked into a relatively narrow range, the amount of fat you eat will vary depending on wheter you want to lose or maintain weight (page 69)
- Choose fats that are easy to burn. See what what the body likes to store for use Thus, emphasis MUFA and SFA: (page 71, 72)
- 55% Monounsaturated fatty acid (MUFA)#
- 27% Saturated fatty acid (SFA)#
- 18% Polyunsaturated fatty acid (PUFA)#
- A 50:50 mix of butter and olive oil approximates the composition of triglycerides typically found in human body fat
- Saturated fat is not bad for you (page 72)
- Current evidence shows no association between dietary SFA intake and cardiovascular disease (page 72)
- There is increased risk associated with increased amounts of SFA circulating in the blood (page 72)
- Intake of SFA does not determine blood level
- A low carb high fat diet significantly decreases circulating levels of saturated fat, because it is promptly burned to CO2 and water (page 72)
- Omega 3 and Omega 6 fats
- Only 1% of these are daily required.
- Most people consume 10 times the required amount of omega-6. Avoid soy, corn, cottonseed, peanut, sunflower, safflower oils, margarines, mayonese (page 77)
- Many barely meet the 1% for omega-3. 1-2 grams of omega-3 per day are optimal. Good sources are salmon, tuna, sardines, herring; ideally 2-3 times per day. Conversion of alpha-linolenate in flax, canola oil to omega-3 in the body is inefficient so supplements with EPA and DHA may be a good idea. (page 78)
- Increasing omega-3 enhances insulin sensitivity, promotes fat burning in muscles, inhibits fat storage, regulate muscle growth, slow muscle and bone loss, augment blood flow to muscles during exercise, with exercise maximize fat loss, increase HDL, improve functioning of blood vessels, decrease muscle soreness and swelling, increase range of motion after damaging exercise (page 73, 74, 75)
- The best oils are low in PUFA, such as olive oil, canola, ‘high oleic’ safflower, coconut, palm (page 75)
- Butter, fat from beef or pork, are excellent choices.
- Other good sources are olilves, avocados, heavy cream, sour cream, nuts, seeds, cheese.
Fluid and Mineral Management
- Salt is a critically important nutrient for athletes, especially on a low carb diet. Routinely take 1-2 grams of sodium per day in the form of 2 bouillon cubes. (page 80, 81)
- When carbs are restricted the body changes from retaining water and salt to discarding them. (page 80)
- blood flow may be impared when salt is not replaced
- The kidney tries to compensate by giving up potassium in exchange for retaining sodium, leading to negative potassium balance. (page 81)
- Loss of water and salt can make you feel sluggish and compromise your ability to perform outdoors in the heat or in the weight room, you can get headaches and feel faint.
- salt depletion causes a compensatory loss of potassium which has a negative impact on muscle mass.
- Potassium (page 82)
- When boiling veggies, potassium is lost in the broth. If you grill your meat, potassium leaves with the drippings. Don’t discard ‘the solution’!
- Enjoy your berries, nuts, seeds.
- Hydration (page 83)
- During the first 5-10 minutes of hard exercise, there is an expansion of the circulation. Once exercising, kidney blood flow goes way down.
- The solution is to drink 1-2 cups (250-500ml) of water about 5 minutes before starting – long enough to be absorbed but too soon for the kidney to start clearing it.
- Magnesium (page 83, 84)
- Not enough causes muscle cramp.
- Magnesium calms muscles (including the heart, nerves, and the brain.
- Potassium is lost in processed food
- the darker green a vegetable, the more magnesium it cointains.
- If you get cramps, supplement with 3 slow-release magnesium tablets daily for 20 days.
- Zinc is absolutely requried for growth, protein synthesis (building muscle), healing, and defense against infection.
- Signs of deficiency are dry skin, horizontal depressions across the fingernails, recurrent skin warts. It is not uncommon in the elderly. (page 85)
- In younger people, there are two causes of zink inadequacy: (page 85)
- rapid growth during adolescence, particularly if eating highly refined foods
- iron: specifically people who are given iron pills due to low blood hemoglobin.
- Taking lots of iron blocks absorption of zinc, even when there is plenty of zinc in the diet. (page 86)
- The solution: take iron only every other month. In the intervening months, take 50mg of zinc (preferable as chloride rather than gluconate) every day.
 Branched-Chain Amino Acids http://en.wikipedia.org/wiki/Branched-chain_amino_acid
 “The ketogenic diet: seizure control correlates better with serum beta-hydroxybutyrate than with urine ketones.” http://jcn.sagepub.com/content/15/12/787.short