Muscle Sport Magazine


By Leigh Penman – 

The subject of low carb diets versus high carb diets when it comes to building muscle and losing fat has probably gained more coverage in the muscle world than Brittany Spears shaving her head did in the celebrity gossip mags. It seems everyone has an opinion when it comes to carbohydrate intake. Some say it is vital to the muscle building process, whilst others think it is as important to building muscle as the weather forecast is to a goldfish!

So just what is the truth when it comes to this controversial macro nutrient?

In this two part series we will look at both sides of the carb coin…first of all:


Low carbohydrate diets are often referred to as ‘ketogenic diets’ since, when carbohydrate intake is restricted, the body produces ketones such as acetone, acetoacetate and beta-hydroxybutyrate. A very important aspect is the Low Carb Diät

These ketones serve as energy sources for the brain and nervous system (which are normally fueled by glucose). They are also very effective when it comes to suppressing the appetite center in the brain – making dieting a little easier. In addition to this, ketones are known to create an improved sense of well-being and even create a mild state of euphoria – which is not a condition normally associated with the process of dieting!

Recent research has also shown that the increased blood ketone levels evidenced in high-protein, low carbohydrate diets make it easier to deal with calorie restriction because hunger is less of an issue. This cannot be said for a diet that is high in protein and moderate in carbohydrate – which usually leaves the dieter in a constant state of hunger and willing to sell their soul for a cupcake!


Free Radicals are produced in response to just about every metabolic process your body executes on a daily basis – even breathing and digesting food leads to their production. These free radicals are responsible for tissue destruction and accelerating the aging process. It is now known that free radicals also attack cells in the brain that control appetite. This results in a constant feeling of hunger that remains regardless of how much you have eaten. Of importance in terms of this discussion is the fact that the action of free radicals on the appetite center in the brain is greater on consumption of a meal high in carbs. Which is another good reason for cutting carbs when it comes to accelerating weight loss and controlling hunger.

CHEATERS CLUB…When to use carbs to your advantage

When you are following a low carbohydrate diet the body produces very little insulin. Now, whilst a low insulin environment is great for fat loss, it can also have a negative effect on the production of thyroid hormones. Put simply, when insulin levels are low due to low carbohydrate intake, the conversion of T4 (inactive thyroid hormone) to T3 (active thyroid hormone) is reduced measurably. This can be avoided by including one hi-carb meal a week, which effectively spikes insulin levels enough to kick-start the thyroid gland into action. The key word here is ONE hi-carb meal a week. Any more than this and you will create too much insulin and increase the likelihood of fat storage.

Oh, and whilst on the subject of insulin, there are some people who claim that insulin is necessary to preserve muscle tissue. This is simply not true. When insulin levels are low the body increases its production of growth hormone. When GH levels are increased the liver produces greater amount of IGF-1 (insulin-like growth factor 1). IGF-1 is far more anabolic than insulin as it drives amino acids, glucose and essential nutrients into muscle cells assisting in their repair and growth.


So, in terms of the ‘great carb debate’ it would seem that, when it comes to contest dieting, low-carb is definitely the way to go. However, there are times when you can benefit from having more carbs in your diet and we will discuss that in part 2 coming up next week!

Leigh Penman began her writing career in 1980 when she started her own weekly music column in a Scottish newspaper. From there she went on to writing for all the major music publications in the UK at that time, including ‘Record Mirror’, ‘Sounds’, ‘New Musical Express’ and ‘Number One’. Her work included interview such celebrities as Madonna, Cher, Tina Turner and David Bowie.

The late 80’s saw her moving into writing for nutrition companies and eventually bodybuilding magazines. She rapidly gained a reputation as being one of the top female writers on the bodybuilding scene and was a contributing editor on ‘Muscle & Co’, ‘Bodybuilding Monthly’, ‘Strength Athlete’, ‘Health & Fitness’ and ‘Fit Body’. She was also a major contributor to the Arnold endorsed magazine ‘Bodypower’ –where she went on to establish the position of ‘Show business Editor’. In addition to this she held the position of Ladies Editor for ‘Physiques International’

In between all this she has written for Personal Development magazines and organizations –including Tony Robbins UK division. Has collaborated on book projects with Leslie Kenton –the original Raw Food and female empowerment guru – and written for computer magazines…..and now she is with Natural Bodybuilding and Fitness magazine,, RX, Species Nutrition and of course!

She is a certified personal trainer, hypnotherapist and has been working out since the age of 15.

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