Many of us at some stage have tried to lose weight, whether it is to fit into a certain dress or to lower blood pressure. In an attempt to lose weight quickly, diet books, magazines or websites that promise rapid and instant weight loss continue to be popular.
One of these diets is the high protein/low carbohydrate diet, luring people to ‘the zone’ or ‘new revolution’. But do these diets really work and what are the effects of eating large amounts of protein and avoiding carbohydrates?
Protein is an essential nutrient used to make enzymes, hormones and antibodies. However, carbohydrate is also essential for our bodies, providing energy and the major ‘brain’ food – glucose.
High protein /low carbohydrate diets generally recommend avoiding fruits, vegetables, wholegrain breads and cereals and legumes, and eating protein from eggs, meats and purified protein sources.
Do they work?
Initially, people can lose a significant amount of weight by eating lots of protein and minimal amounts of carbohydrate. However, the weight loss that occurs is usually due to water loss, not fat loss. In addition, as carbohydrate intake is limited, the body uses other fuels to make energy, such as fat. The result is the development of a metabolic condition known as ketosis, which means bad breath and loss of appetite, and without all the fruits, vegetables and grains, constipation is likely as well.
The combined effects of severely reduced food choices and loss of appetite is undoubtedly going to be a reduction in energy (calorie) intake. However, it certainly is still possible to reduce energy intake while still enjoying a wide variety of great tasting and healthy foods.
What are the long-term effects?
These types of diets can lead to a reduction in the body’s metabolic rate (the rate we burn up energy), as muscle tissue is also broken down for energy. Because these diets are difficult to stick to long term (even bacon & eggs every day can get boring), when people return to their usual eating habits, our body doesn’t burn up the energy as efficiently and the weight returns.
What are the effects on the heart?
The long term effects of high protein diets are unknown, however a recent study found that LDL (bad) cholesterol levels rose significantly when following one of these diets. A high LDL cholesterol level is a significant risk factor for heart disease. It’s not surprising that this effect occurred, as many high protein foods are also high in saturated fat and cholesterol (such as fatty meats and eggs), but lack soluble dietary fibre and other compounds thought to lower cholesterol.
It is concerning that the very foods that these diets tell you to avoid are those that have a wealth of research indicating they actually protect us from heart disease!
The best way to achieve weight loss is to eat plenty of fruits, vegetables (including legumes) and wholegrain breads and cereals, moderate amounts of dairy or soy products, nuts, eggs and if desired fish and lean meats, and to limit foods and drinks high in refined sugar, fats & oils and alcohol. Not only has this type of eating been shown to promote long term heart health, the variety of food flavours and textures make healthy eating delicious.
This article was prepared by the nutritionists at Sanitarium Nutrition Service.