The common goal of ketogenic (low-carb, fat-rich) dieters is to achieve ketosis, also known as “nutritional ketosis.” Ketosis refers to the metabolic state in which there is a higher concentration of ketones in the blood as the body uses certain ketones (ketone bodies) as the major source of energy to fuel itself.
The body can use 3 different sources of energy: carbohydrates, fats, and proteins. Its first choice of energy source is carbohydrates because it can be quickly broken down into usable energy. However, when the body is deprived of its normal share of carbohydrates
When blood ketone levels are measured to be between 0.5 and 3.0 mmol/L, the body is considered to be at nutritional ketosis. The body can achieve ketosis by other methods than ketogenic diet, such as fasting and exercise. Some enter ketosis in as little as 12 hours, but for others, it may take up to a week or longer.
Signs of ketosis
The most definite way to know whether the body is in ketosis is to measure blood ketone levels. Other symptoms that the body may show during ketosis include the following:
– Keto flu
- Difficulty sleeping
- Brain fog
- Muscle cramps
The keto flu includes a group of undesirable symptoms like the ones listed above. Also known as signs of “carbohydrate withdrawal,” most of these symptoms happen in the initial stages of ketosis as the body transitions its primary energy source from carbohydrates to fats.
Dehydration and/or a lack of sodium and potassium due to electrolyte imbalance seem to be the leading explanation behind many of these symptoms. In the case of muscle cramps, for example, electrolyte imbalance can cause problems in the nerve cells that send electrical impulses. Those suspecting a “keto-flu,” are recommended to replenish hydration and electrolytes through supplements or potassium-, magnesium-rich foods.
– Bad breath
As fat metabolism is ongoing, acetone, the byproduct of fatty acid metabolism, is exhaled, producing a slightly sweet and fruity breath, characteristic of a nail polish remover.
– Rapid weight loss
While ketone level of 0.5-3.0 mmol/L is the standard for nutritional ketosis, ketone level of 1.5-3.0 mmol/L is considered to be the optimal ketosis for weight loss.
– Lack of appetite
Ghrelin is the signal hormone for hunger. Some studies show that rise of ketone levels may inhibit ghrelin, leading to appetite suppression.
– Frequent urination
The body will work harder to excrete excess ketones in the process of breaking down fat through the means of urination.
– Increased energy and focus
Once the body has been in a steady state of ketosis, the brain also starts to use ketones, which has been reported to be more efficient of a fuel than glucose.
– Change in bowel movements
A sudden change in diet may add stress to the gut, leading to either constipation or diarrhea. This may be due to a variety of reasons, including lack of fiber, lack of probiotics, and greater demand for fat digestion.
Benefits of ketosis
Weight loss is the primary effect of ketosis. As soon as the body starts to effectively burn fat for fuel, it will quickly lose weight with fat loss. A study indicates that a long-term ketogenic diet may also lower levels of LDL cholesterol and triglycerides.
Aside from weight loss, ketosis is being studied for its therapeutic effects, such as improved insulin sensitivity, neuroprotective properties, and reduced inflammation. For some illnesses, including type 2 diabetes and epilepsy, ketosis has already been established as an effective tool of treatment.
Dangers of ketosis
When a body reaches and remains at the “nutritional ketosis” state, it is considered safe due to the small concentrations of ketone production. However, when balance tips overboard and ketones become too concentrated in the blood (blood ketone level above 3.0 mmol/L), it is in the danger of entering ketoacidosis (DKA) as it changes the blood pH into an acidic state. Some symptoms of ketoacidosis are excessive thirst/dehydration, fatigue, increased urination, trouble breathing, confusion, stomachache, vomiting, dry skin, and fruity breath. Since ketoacidosis is a potentially fatal condition, ketone levels should be monitored daily and those who suspect ketoacidosis must seek immediate medical attention. Hydration is also important in helping to prevent ketoacidosis, as this can dilute the blood pH.
Long term implications of ketosis are currently quite controversial and less clear. Conventionally, there are studies that show heavy fat and protein metabolism of ketosis may exacerbate the conditions of certain organs, especially the pancreas, liver, gallbladder, and the kidneys. There are also debates of how sustainable this diet is due to concerns of nutritional deficiencies. Therefore, such changes in diet plans should be discussed with and assisted by expert dietitians and/or medical providers.
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