Among the many weight loss plans that have come and gone over the years is one that stresses a low intake of carbohydrates complemented by a high intake of protein. While this diet was popular in the late 1990s (going under the name of Atkins diet) then waned, it is currently being promoted in a slightly different form. The diet emphasizes foods high in protein and fat such as meats, poultry, fish and eggs and excludes or limits most grains, legumes, fruits, breads, sweets, pastas and vegetables (and sometimes nuts and seeds), foods which are high in carbohydrates (both complex and simple). Does this diet work for weight loss, and further, does it have other health benefits? Since it seems drastic to cut out several entire food groups, the question that must be asked is: are there any negative effects in following the diet?
In a regular well-balanced diet, the body uses carbohydrates as its main fuel (energy) source. Sugars and starches from breads, cereals, fruits and vegetables are broken down into simple sugars during digestion and absorbed into the bloodstream where they are known as glucose. As glucose levels rise, the body releases insulin which helps glucose enter cells to fuel metabolic actions and muscle movement. Excess glucose is stored in the liver, muscles and other cells for later use – or alternatively is converted to fat. To describe a complex chain of interactions in simple terms – the idea behind a low-carb diet is that decreasing the intake of carbohydrates will lower insulin levels which causes the body to burn stored fat for energy and ultimately leads to weight loss.
Turns to protein
In lieu of carbohydrates, the body turns to protein and particularly fat as an energy source. When not enough glucose is available, molecules called ketones are generated as fat metabolizes and are used as energy. Thus the low-carb diet is sometimes known as the ketogenic diet.
There are many testimonials of people who have lost weight on low-carb diets – in spite of the emphasis on fat intake – and studies show how this could, in fact, be possible. First of all, individuals may shed weight because they eat less since extra protein and fat keeps one feeling satiated longer. As well, because of lower insulin levels on a low-carb diet, the kidneys start shedding extra sodium which gets rid of excess water and results in weight loss (rapid in the first week or two).
While dropping excess weight is of benefit to everyone since obesity carries with it increased risks for cardiovascular disease and some types of cancer, a ketogenic diet appears to have several other health benefits. Studies have shown diets low in carbs may help lower blood tryglcerides (fat molecules) and increase levels of HDL or so-called “good cholesterol” (while at the same time improving the pattern of LDL or “bad” cholesterol) both of which would help maintain a healthy blood pressure and overall lower the risk of heart disease. In addition, people who experience “insulin resistance” – that is, their pancreas produces low levels of insulin – benefit from low carbohydrate intake, avoiding the development of type 2 diabetes.
Since the brain is able to effectively use ketones instead of glucose for its functions, the ketogenic diet has for decades been used to treat epilepsy in children who may not respond to drug treatment. This means, of course, the diet may have therapeutic effects on other brain disorders such as Alzheimer’s and Parkinson’s diseases.
Missing nutrients
Are there any negative aspects to following a low-carb high-protein diet? The obvious drawback is the range of nutrients missing from a diet lacking fruits, vegetables and whole grains. Some of the vitamins and minerals are available in meat products, but not in quantities needed by the body. Over the long term this may result in serious deficiencies, bone loss and gastrointestinal disturbances. Another concern is lack of fibre found in high carb foods which aids in digestion and elimination by providing bulk.
Severely restricting carbohydrates which results in ketosis (when the body breaks down stored fat and ketones build up) can include side effects such as nausea, headache, mental and physical fatigue and bad breath.
It should be noted that the modern diet is often excessively high in carbohydrates which is harmful especially when the emphasis is on sweet foods, low-fibre cereals, soda pop and processed foods. A conscious effort to curb the intake of simple sugars should be encouraged. However, whole grains, fruits and vegetables have a place in a healthy diet. If you choose to try a low-carb high-protein and fat diet to lose weight or to get your carbohydrate intake under control, the diet should be of short duration – not more than a few months. Those wishing to follow the ketogenic diet for a longer time should be monitored by a health coach who has access to a body composition analysis machine which can track things like percentage of body fat and muscle mass as well as hydration levels.
