The Truth About Carbohydrates And Fat Loss

When someone decides to lose body fat whether it is for summer, an event or simply to improve their health, one of the first changes they consider making is to their eating habits. Once the decision is made, the next step taken is to research their possible diet options. This may involve speaking with people, reading magazine articles or visiting their local book store in order to find the ‘holy grail’ of diets- the diet that is guaranteed to shed fat off their body quickly and with little effort.

Of course a diet-only approach to fat loss is futile in itself but to make matters worse, dieters often become hopelessly confused about what to eat for the best results. Should they reduce their fat intake? Cut out all their carbohydrates? Eat only soup for a few days? Eat based on their blood type? Follow a de-tox diet? Liver cleansing? The options are endless.

The area that probably has dieters baffled the most is the issue of carbohydrates. Currently there are two dominant schools of thought when it comes to carbohydrate consumption.

On the one hand, we have dietitians and nutritionists telling us for the last 20 years that carbohydrates don’t make us fat. This view is clearly stated in their promotion of the USDA’s Food Pyramid and in more recent times, The Australian Guide to Healthy Eating pie chart. Both of these food guides recommend the majority of food intake come from refined carbohydrate sources, like bread, pasta, rice, cereals and other grain-based food products. In fact, the USDA Food Pyramid recommends we eat 6-11 serves a day of these carbohydrate sources in order to have a healthy diet! The advocates of this style of eating are often heard to say things like, ‘Carbohydrates don’t make you fat, it is what you put on them that makes you fat.’ Examples include, sour cream on potatoes or butter on bread.

On the other hand, there are the advocates of low-carb diets. Popularised by Dr Robert Atkins in the 70’s (even though their use has been documented for at least 150 years), low-carb eating appears to be experiencing a re-surgence. This is due mainly to the fact that many Hollywood celebrities have confessed to using them to achieve their movie-star bodies. As a result, the market is being flooded with low-carb diet books and an amazing array of low-carb products, including meal replacement bars, cookies, muffin mixes, cereal products, pizza bases and many others. Often these diets allow an almost unlimited amount of food so long as carbohydrates are restricted.

These diametrically opposed views often leave people hopelessly confused about what to eat to achieve maximum fat loss. In this article I hope to clear up the confusion so you can enjoy your food whilst at the same time lose all the body fat you want.

Insulin and glucagon

In considering carbohydrate and its affect on our body fat stores, we must firstly understand the function of two hormones, insulin and glucagon. Both of these hormones are produced by the pancreas (an organ that sits behind the stomach) and work in concert to regulate our blood glucose level. For example, when our blood glucose level rises (after a meal), insulin is the hormone responsible for storing the glucose and normalising the blood glucose level. When the blood glucose level falls, glucagon promotes the release of glucose from the liver, bringing the level back up again.

For fat loss to occur, insulin release must be minimised as much as possible because of the effects it has in the body, which include:

• Promotes the storage of nutrients in cells (positive effect- anabolic).
• Promotes the storage of fat in the adipocytes (fat cells).
• Promotes the uptakes of glucose into the adipocytes and their conversion into fat.
• Increases the activity of fat manufacturing and fat storing and enzymes (lipoprotein lipase - LPL and fatty acid synthase - FAS).
• Inhibits the release of fat from the adipocytes (which could be used as a fuel source).

Insulin is released as a result of mainly two factors and the amount of insulin released is in direct proportion to these two factors.

•The size of a meal.
•The amount of glucose in the bloodstream.

Accordingly, eating smaller, more frequent meals may help to reduce the insulin response (i.e. eat 5 small meals a day).

Also, regulating the amount of glucose entering the bloodstream will help. This may be achieved by:

• Reducing the portion of carbohydrate in each meal.
• Emphasising low Glycaemic Index (GI) carbohydrates.
• Emphasising low-density carbohydrates.
• Ensuring each meal contains a portion of protein, fat and fibre as well as the carbohydrate.

Reducing the portion of carbohydrate in each meal

Since insulin is released in response to an increase in blood glucose and fat loss will be maximised if insulin is low, people may be forgiven for thinking that a low-carb diet is the answer. Whilst it is true that these diets do promote fat loss, I do not recommend them for the following reasons:

•They are too hard to sustain long-term.
•They may lead to deficiency diseases due to their avoidance of fruits and vegetables.
•They may negatively affect bodily functions due to a reduced fibre intake and possible high intakes of saturated fat and cholesterol.

Despite the possible negative consequences of low-carb diets, the overall philosophy of reduced insulin response is sound. Therefore, people wanting to lose bodyfat should reduce (without eliminating) their portion sizes of carbohydrate in every meal.

Emphasising low Glycaemic Index (GI) carbohydrates

The GI is a score given to carbohydrate-containing foods based on how rapidly they cause a rise in blood glucose after being consumed. A high GI means the food causes a rapid rise in blood glucose and a low GI means the food causes a more sustained release of glucose into the bloodstream.

Since a rise in blood glucose promotes insulin release we should emphasise low GI carbohydrates in our diet. See Table 1 for more information.

Emphasising low-density carbohydrates

Carbohydrate density describes the amount of carbohydrate a food contains per serve. For example, pasta (high-density) contains 76.5 grams of carbohydrate per 100 grams whilst broccoli contains a minuscule 0.5 grams per 100 grams. Obviously the greater the carbohydrate density the greater the likelihood of the food causing a rapid rise in blood glucose, and in turn, insulin as well. See Table 2 for more information.

Ensuring each meal contains a portion of protein, fat and fibre

Not only does having protein, fat and fibre with the carbohydrates ensure a more ‘nutritionally complete’ meal but these nutrients also have the effect of slowing down the absorption rate of the carbohydrates, which allows a more sustained release of glucose into the bloodstream and therefore a reduced insulin response.

Quite often people will have a piece of fruit, a diet yoghurt or a low-fat muffin for their mid-morning or mid-afternoon meal in their quest to lose body fat. Unfortunately, these foods alone don’t provide an adequate amount of all the nutrients required by the body and may also cause a rapid rise in blood glucose, halting fat loss in its tracks!

As a result, these foods should only be consumed with other foods to ensure a complete meal. For example, have a piece of fruit with some nuts, mix a small amount of cottage cheese with the yoghurt (it doesn’t taste that bad- honest!) or have a low-fat muffin with a protein shake.

From this information it is safe to conclude that following a diet based on the Food Pyramid or Australian Guide to Healthy Eating perhaps isn’t the best way to assist our fat-loss efforts. Furthermore, a big question to ask yourself is this:

‘Since the Food Pyramid was designed by the United States Department of Agriculture (USDA), do their interest lie in looking after our health or in supporting the economy?’
[NOTE: The base of the Food Pyramid recommends 6-11 serves a day of high density, mostly high GI, refined, grain-based carbohydrates.]