Eating for weight loss
Not every martial artist need to lose weight, but many do. This article aims to give readers some of the information that I used to drop over 12kg when the penny finally dropped that my weight was preventing me from reaching my full potential as a martial artist.
Feed the machine
The body is a very adaptive machine. Give it too much energy to use and it will store it as fat, but give it too little and it will slow down so that it requires less energy. Everyone knows someone who has been on a strict calorie restricted diet who having reached their goal weight ballooned even heavier than their stating weight once they finished the diet. There are a number of factors to this phenomenon, but one of the important ones is the effect of starvation on the body.
To simplify things the metabolism is the rate the body uses energy. This is not a fixed rate and can be adjusted through diet and exercise. If the body goes an extended time (over 3 hours) without food the body simply slows down the metabolism to accommodate what it perceives as a famine. In short don’t eat regularly enough and you start to require less calories, but what happens when you eat your next meal? Nutritionists often refer to this as the body entering starvation mode. The body having experienced a famine stores energy in the form of fat for a later famine event.
The greater amount of muscle mass we have the higher the amount of energy needed to sustain it. Even a moderate amount of weight or other resistance training can increase your muscle mass sufficiently to increase your metabolic rate as well as burning additional calories whilst performing the exercises.
Unfortunately for those that try to starve themselves thin one of the energy sources that the body turns to when food is scarce is muscle. Not only will you lose fat, the amount of calorie burning muscle is reduced as the body cannibalises it for energy. This is one of the factors why people then rebound heavier than they were before the diet because their lower muscle mass burns less energy than they did before the diet creating a significantly larger gap between what they consume and what they need to maintain homeostasis.
All fats are not equal
Fat has twice the calorific value than either carbohydrate or protein and yet are an essential part of any nutritionally balance diet. Without fat in our diets we would be deficient in a variety of nutrients including essential fatty acids. This can lead to a number of health complications including dermatitis and problems with blood pressure.
From a weight loss perspective a very low fat diet can result in loss of muscle mass because of an increase in protein breakdown and leave us with insufficient energy to be able to exercise effectively.
What we do need to manage is the type of fats we are eating. There are three different groups of fats. These are saturated, monounsaturated and polyunsaturated. Saturated fats are characterised by being solid at room temperature and are considered a culprit for heart disease because they increase cholesterol in the blood. To achieve peak performance and health we should avoid saturated fats. Sources for saturated fats are fatty red meats, cheese and butter.
Monounsaturated fatty acids are usually liquid at room temperature, but may solidify at cold temperatures. They are thought t have the greatest health benefits of the three types of fatty acids and can reduce our cholesterol levels. The richest sources for monounsaturated fat is almond, olive, rapeseed, hazel nut and groundnut oil, avocados, olives, nuts and seeds. It is recommended that 12% of our daily calorie intake is from these sources.
Polyunsaturated fatty acids are liquid at both room and cold temperatures. They reduce bad LDL cholesterol, but if eaten in excess will also reduce good HDL cholesterol slightly. This fatty acid is found in fish oil and most vegetable oils. For this reason it is recommended that we do not eat in excess of 10% of our daily calorie intake from this source.
One of the advantages of eating fat is that it reduces feeling of hunger for longer and slows down the digestion of carbohydrates. This is an important factor in how we use or store the calories we get from that food source.
Carbohydrate ‘Fast is not always good’
Carbohydrate is an energy source that is broken down and stored as glycogen in the muscles. This is the primary energy source used by all athletes and one that needs to be developed. However if we simply try and do this by packing in more carbohydrate based calories into each meal the body will simply store what it does not need as fat.
Now an additional factor in this storage / use process is how quickly the body can break down the carbohydrate and turn it into energy. Carbohydrate is broken down into two categories. Simple carbohydrates are found in the various types of sugars. These are quickly released by the digestive process and produce an energy spike. If the amount of energy produced is greater than being used it is stored as fat. Sources include potatoes, white rice, wheat (pasta / bread), dairy, fruit and refined sugar.
Complex carbohydrates are slower to release and produce a longer sustained energy release. This reduces the risk of there being excess energy available from this source and makes it less likely that there will be fat storage from its consumption. However eat too much of this type of food source at one time and you will get fat storage in response. Sources include whole grains, brown rice and starchy vegetables such as sweet potato.
Whether Complex or simple the size of their portions in meals needs to be restricted so that excess calories are not stored as fat. This is particularly the case with foods that release their energy quickly. These are often called high GI foods as opposed by slow release foods that are referred to as being low GI.
Most sensible diet plans recommend eating a number of pieces of fruit a day due to the amount of dietary fibre and other nutrients they contain. Though for weight loss the type of fruit and portion sizes need to be given some thought. Apples and berries such as strawberries and raspberries are both low GI foods and therefore suitable for a weight loss diet. Fruits such as pineapple and banana both release their energy very quickly and their consumption in large quantities are going to lead to excess calories being stored as fat.
Another thing to avoid is fruit juice. Often artificially sweetened it also lacks the dietary fibre that a whole piece of fruit contains. It is this fibre that slows the rate of absorption of the fructose sugar in a piece of fruit when we eat it and therefore fruit juice is very high GI and to be avoided if we are trying to cut weight.
Protein ‘More than the building blocks of muscle’
Most people know that protein is an essential component in building muscle and for that reason a vast industry supplying protein supplements to the fitness industry exists. Whether there is a need to supplement is hotly debated within the fitness industry because most of the research supporting supplementation has been done by the people making their living through supplying these products, but from a weight loss perspective eating high quantities of protein has a number of benefits.
First protein has a high thermogenic effect. That means it takes a lot more energy to digest and causes an increase in the metabolic rate. Second the consumption of protein along with carbohydrate slows the absorption of the carbohydrate lowering the total GI (Glycaemic Index) of the meal.
Finally excess protein is not stored the same way as the body. Any additional protein is simply excreted by the body in urine. One unfortunate side effect of this process has been experienced by people who favour a protein only diet such as the Atkins diet. If your body is not able to excrete the excess protein fast enough it starts to use the moisture in your breath and sweat on your skin to help. As one personal trainer I know put it they followers of these diets can leave you smelling like a toilet as your body struggles to cope with the load.
The last important factor is that protein consumption has been proved to leave us feeling fuller for longer. This prevents unnecessary snaking and makes it easier to reduce overall calorie consumption.
Fancy a drink?
Alcohol cannot be stored in the body and has to be oxidised and converted into energy. This process suppresses the body’s ability to oxidise both carbohydrate and fat. This means they are both channelled into storage instead of being used as an energy source.
Alcohol provides 7 kcal/g unlike protein and carbohydrate which both provide 4 kcal/g. This tends to mean that alcoholic drinks are relatively high in calorific value compared to a similar volume of none alcoholic drink. Also both beer and wine contain a large quantity of sugar and this means they are high GI and the energy is likely to be stored as fat.
I have already explained the dangers of cutting calories dramatically however a small decrease in calorie consumption below what our bodies need to function will produce a safe and sustainable weight loss. Remember rapid weight loss probably means you are losing muscle and not fat. This will only make the rebound worse if you re-establish eating habits that has got you in this mess in the first place.
The general rule I use is to eat a nutritionally rich diet, low in saturated fat and sugar. Meal size is reduced to allow the body the best chance of using the energy it provides and meals are eaten every 2 to 3 hours depending on hunger. Hi GI foods are removed from my diet as much as possible and whilst focusing on weight loss give up the booze. There is a time and place for a social drink during the maintenance phase once you have reached your target weight.
In a future article I will discuss how to maintain weight and have a life beyond diet and the sorts of foods I like to eat and why.
The Complete Guide To Sports Nutrition - Anita Bean
Nutrition for Dummies - Nigel Denby