Reduction in overall calories is key to weight loss 

Many popular diet plans sold in bookstores, or featured in magazines, promote high protein/low carbohydrate eating as the key to successful weight reduction. As a result, all carbohydrate foods have been tarred with the same brush and effectively vilified by the media; a situation perpetuated by celebrity endorsement of these diets. So do these high protein/low carb plans actually work for weight loss and are they better than the conventional low fat, high carbohydrate healthy eating plan that is rich in fruit and vegetables?

Some studies suggest they do promote greater weight loss, however, findings from other studies disagree. The main problem is studies often aren’t well enough designed, or they don’t have enough people in them to prove definitively one way or another. Also, hardly any studies last beyond a year, so it’s difficult to tell long term which is the best.

However, an interesting clinical trial was carried out in the US, and findings were just published in February of this year. In this study, researchers assigned over 800 people to one of four diets:  (1) low fat/ moderate protein/high carb, (2) low fat/high protein/moderate carb,  (3) high fat/moderate protein/low carb and  (4) high fat/high protein/low carb. Researchers observed the people in this trial for 2 years as they followed their individual plans. All of the diets were calorie controlled. The researchers found that people lost weight if they ate less calories than they were burning off through activity, regardless of whether their calories were made up of mostly protein, carbohydrate or fat.

Why do high protein diets seem to lead to more rapid initial weight loss? Carbohydrate is the body and brains’s preferred source of energy. We store carbohydrate in our body as ‘glycogen’, in our muscles and liver. Glycogen is stored with water. When our body no longer is being supplied with carbohydrate through the diet, it switches to using glycogen stores for energy. As we use up this limited supply of energy, we lose the water it is stored with. Hopping on a scales after a week of avoiding carbs may indicate you’ve lost pounds. But this is actually mostly water loss. Resuming eating carbohydrates will immediately reverse this, resulting in normal levels of water retention and so the weight goes back on and you are very unhappy.  There is also the theory that  high protein diets may also satisfy the appetite more, and so people end up eating less when following them. However, the study mentioned above did not find any difference in appetite between those on a high carbohydrate plan and those on high protein plan.

What is the down side of following a low carbohydrate plan? All carbs were not created equally. Complex or ‘starchy’ carbohydrate foods include bread, cereal, potatoes, porridge, pasta, rice and noodles. Wholegrain versions are packed with fibre, B vitamins, vitamin E, minerals and phytochemicals. Carbohydrate is also found in nutrient packed fruits, peas, beans and lentils. Fruit and vegetables are rich in vitamins, minerals, antioxidants and phytochemicals. Basing our meals on wholegrain and eating 5 servings of fruit and vegetables daily as part of a healthy balanced diet has been shown to be protective against weight gain, heart disease, type 2 diabetes and certain cancers. Sugary carbs include table sugar, sugary drinks, sweets, biscuits and cake. These foods provide energy, but little else in the form of micronutrients. Many of the ‘low carb diets’ out there give the impression that all carbohydrates are the same and should be avoided, advocating as little as 20g carbohydrate daily. However, the American Heart Association advises a minimum of 100g of carbohydrate daily, to ensure overall nutritional adequacy.

The last word If you are trying to slim, the best approach is to aim for slow gradual weight loss (1-2lbs or 0.5-1kg per week) with healthy levels of physical activity combined with a a balanced diet (with an adequate intake of carbohhydrate from wholegrains such as bread, pasta, rice in addition to fruit, veg, peas, beans and lentils). Drastic weight loss due to fad diets very often ends up being short-term, and can lead us down a frustrating road of yo-yo dieting.

We have many clients who come to us after many frustrated years of trying this and that diet. If you are struggling with weight loss, or would simply like to improve your diet, contact us to make an appointment for a personal one-to-one consultation.

© NutritionWise