By Lynn Clay, Sports Nutrition Consultant
Is your lycra being challenged after an over-indulgent Christmas or are you just in need of losing a few pounds to improve your performance? Either way, it can be difficult to decipher the easiest way to lose fat without it negatively affecting your performance. Should you adopt a high carbohydrate, calorie restricted diet, or is a higher protein diet superior for achieving weight loss? Let’s take a look at the facts.
The traditional high carbohydrate diet. It is well documented that a high carbohydrate diet is beneficial to supply energy for endurance sports such as cycling, aiding performance progression, recovery and providing immune system support. In fact, most data recommends that around 60% of daily food intake comes from carbohydrate with only 20% being derived from protein and 20% from fat. Steady weight loss = reduce calories by 500 per day, whilst maintaining the same training load, to encourage a weight loss of 1 to 2 pounds per week. Or remain on 2500 calories but increase training load by an extra 500 calories per day or drop calories by 250 and increase calorie burn by 250. The decision is yours and the end result will be the same. Seems simple, but according to research this may not be the best method for periodic weight loss. One of the limitations with this method is that in periods where calorie intake is not sufficient to meet energy expenditure, the body mobilises protein from muscle tissue and converts it to a carbohydrate energy source in the liver. The effect of this may be weight loss, but where energy is in high demand, this can reduce lean muscle to fat ratio, which can have a negative effect on performance.
Protein balance. So, what is the alternative? What about the merits of a higher protein diet, to encourage muscle retention? We’re not talking Atkins here, but just increasing the protein content of your diet to around 30% of total calorie intake, with carbohydrate intake dropping to 50% and fat still making up 20%. In a trial carried out in the Journal of Nutrition, two groups of participants consumed calorie restricted diets with low or moderate protein intake along the guidelines discussed. In the low-protein, high carbohydrate group, 7kgs of weight was lost over a 10-week period. In the moderate protein group, average weight loss increased during this period to 8 kilograms, a small, but statistically insignificant increase. However, when body composition was analysed, it was found that the low protein group lost 30% more lean body mass (muscle) and 20% less fat. This would indicate that a moderate protein diet is superior for muscle preservation and fat loss, although both diets, when calorie intake is reduced, will lead to weight loss. This is significant for anyone who wants to accelerate weight loss for short periods of time and maximise their power-to-weight ratio. When the target weight loss is achieved however, and the diet no longer has reduced calorie content, it is wise to increase your carbohydrate intake to 60% once again, so that energy supplies are not limited. It is also important to implement the lower carbohydrate, higher protein diet in periods when you are not racing. In this way, you can get the best of both worlds; superior fat loss and muscle retention in dieting periods and maximum energy during competition and hard training.
Appetite control. It is hard to cut calories post-Christmas. Hunger and cravings often win the battle and you end up tucking into sweet foods. But there is an easy way to control cravings:
Regular meals. Eating your food across only three meals or missing meals during the day can lead to blood sugar fluctuations. If you eat a high carbohydrate breakfast, lunch and dinner, but don’t snack in-between you will find that you may have poor concentration and energy levels mid-morning and mid-afternoon and that you will be likely to crave sugary foods around these times. Eating your meals across five sittings, incorporating three meals and two snacks can help to stabilise blood sugar levels so that you have more constant energy levels throughout the day and your cravings subside and so, you can make much more sensible decisions about which foods to select.
Go low GI apart from after sport. Ideal foods for assisting stable blood sugar levels are low glycemic - carbohydrate foods such as wholegrain breads, basmati or long grain brown rice, couscous, whole-wheat pasta, beans, lentils, fruit and nuts. Generally white foods such as white rice, white pasta, white bread and white potato have a higher glycemic index and therefore are not perfect for the general diet. You can, however, reduce the glycemic response of a moderate or high GI food by combining it with protein and fibre. The easy lesson learned from this is to include protein and salad or vegetables with each meal’s carbohydrate. In the immediate period after exercise your needs differ and your carbohydrate stores will be more adequately replenished if you select high GI foods or drinks. Implementing this change of percentage protein intake for a short period of time (4 to 6 weeks) with either a reduction in calories, an increase in training load or a mixture of the two will aid fat loss whilst protecting your valuable muscle. Try it and you’ll be back to your old self in no time.
