We have expressed some concerns with fad diets, such as low-calorie crash diets (“Crash diets—losing weight at the heart’s expense?” Philippine Daily Inquirer, Feb. 8, 2018). Crash diets have been shown by CMR (cardiovascular magnetic resonance) to be associated with deterioration of heart function.
This deterioration has been noted even in people with no known previous heart problems. The adverse effects on folk with already diseased hearts can be disastrous. Although it’s a very effective weight-loss strategy, with dieters losing five to 20 pounds a week, starving the entire body, including the hardworking heart, which beats 24/7 nonstop, is a bad idea.
We’d like to clarify, though, that while such crash diets may not really be risky for everyone, it’s also not safe for anyone. So, before one tries it, it’s best to get advice from one’s physician to make sure that one’s heart can handle it.
Is a ketogenic diet another extreme strategy for weight loss like a low-calorie crash diet? Patients have been asking me about it.
A ketogenic or keto diet is a high-fat but very low-carbohydrate diet, as low as 30 grams of carbohydrates per day or even less. In a way, a keto diet may be similar to a crash diet with extreme restriction of carbohydrate intake.
But a keto diet differs from a crash diet in that it provides an alternative source of energy for the body.
State of ketosis
Instead of deriving energy from glucose or carbohydrates, the body shifts to burning body fat, which produces an energy source known as ketones. This process is known as ketosis. So, people on ketogenic diets are in a state of ketosis. This is different from ketoacidosis which can be potentially fatal.
Ketoacidosis indicates an extremely high level of ketones, making the blood “acidic” already. The three most common causes of ketoacidosis are alcohol, starvation and diabetes. And yes, it’s serious. It can cause death.
This is the fly in the ointment for keto diets. It may be recommended, but it still requires some medical supervision, particularly in more senior adults, those with diabetes and other metabolic problems, and those who can’t stay away from alcohol once in a while.
With less carbohydrates to metabolize, there is a lower demand of the body for insulin, which is beneficial for patients with diabetes mellitus. Although some doctors treating young patients with type 1 diabetes (juvenile onset) say it’s safe for them, I don’t recommend it for type 1 diabetics because of their higher risk of developing ketoacidosis, compared to those with type 2 diabetes (adult-onset).
Type 1 diabetics have to be monitored by their physicians if they’re on a ketogenic diet.
Based on current knowledge, carbohydrates are the macronutrient mainly responsible for increasing blood sugar level. Hence, a ketogenic diet restricts its consumption to as low as possible
—lower than the conventional low-carbohydrate diet.
In its place, a moderate protein and a very high fat content are provided in the diet.
With ketone bodies burning fat as the source for the body’s energy, the physiologic consequence is a significant weight loss, around five to eight pounds a month, as I’ve noted in my patients. And that comes with one “cheat day” a week.
I allow a modest intake of something sweet, or an extra serving of carbohydrates during the cheat day to sustain them on the diet, and minimize cravings. Somehow it makes them feel good that they can still have these forbidden pleasures once a week.
Studies have shown that keto diets can help reduce the blood pressure by around 5 mmHg, reduce triglyceride levels, raise HDL cholesterol (the good type of cholesterol) and improve stamina and mental performance.
For individuals at high risk of ketoacidosis like type 1 diabetics, elderly individuals, and those with an acute illness or infection, and excessive alcohol drinkers, the physician may need to monitor the ketone levels and assess the state of ketosis. The ketone level can be measured in the blood, urine or breath.
How about side effects? Any change in the diet requires adjustment or adaptation in the body, and when this happens, some side effects may be experienced by the dieter, including what is called “keto-flu.” This may consist of sluggish thinking or “brain fog,” dizziness, fatigue, loss of energy, palpitations and salivary problems due to cravings.
Other possible side effects are change in bowel habits, usually constipation, leg cramps, and ketone-smelling breath. Most side effects usually dissipate after a few weeks.
The ketogenic diet is contraindicated in patients unable to metabolize fatty acids to produce ketone bodies as an energy source. These individuals must rely on carbohydrates as their primary fuel source. Examples are individuals with metabolic disorders like pyruvate carboxylase deficiency, porphyria and other fat metabolism disorders.
If individuals afflicted with these metabolic problems were to go on a keto diet, their body has to convert protein, not fat stores to energy, leading to ketoacidosis and possible fatal outcomes.
There are some publications recommending ketogenic diets for epileptic children, but not for epileptic adults. I also recommend it to patients with Alzheimer’s disease and other types of dementia and Parkinson’s disease. If they’re not overweight, I don’t restrict the carbohydrates, too.
Statins and keto
How about the use of statins with a keto diet?
Statins are popular cholesterol-lowering agents which have been shown to reduce the risk of heart attacks and strokes.
If an individual really needs statins for their cardiovascular disease risk, then it should be maintained. Statins and keto diets go well together in this group of patients.
But prescribing a young, low-risk person a statin drug just to counteract the increased fats he or she is taking doesn’t really make much sense. It’s more proper to just monitor cholesterol, blood sugar and ketone levels every three months while on a keto diet.
So, are keto diets a boon or a bane? I believe it’s more of a boon, provided you don’t fall into its potentially serious traps, which could make it not only a bane, but a curse.