When providing nutritional advice to a client you must explain the boundaries you have professionally. Any information you produce for a client should be in line with healthy eating guidelines.
Guidelines which need to be followed to achieve a healthy diet:
- Plenty of fruit and vegetables.
- Plenty of starchy foods such as rice, bread, pasta (try to choose wholegrain varieties when you can) and potatoes.
- Some protein-rich foods such as meat, fish, eggs and pulses. Some milk and dairy foods.
- Just a small amount of foods high in fat, salt and sugar.
- It’s also important to eat a variety of foods to make sure we get all the nutrients our bodies need.
Health risk associated with low fat, faddy diets
Physiological consequences of low calorie diets
Nearly all diets are based on calorie restriction, no matter how they are dressed up. Quite simply, in order to lose weight calorie expenditure must be greater than calorie input. The problem is that many diets advise quite extreme calorie restriction in order to guarantee short-term success and it is this “too much, too soon” approach that actually guarantees long-term failure.
Let us consider the following case:
- A female – aged 34, 5ft 4ins, 70Kg (11 stone) wishes to ‘go on a diet’ to lose some weight.
- A magazine advises that a 1,000 kcal per day diet will lead to a weight loss of 6 to 8 lbs in one week.
First of all let us work out how many calories she would need to consume in order to provide her body with it’s basic requirements for energy.
BMR: 70 kg x 25 kcals = 1,750 kcals
Activity level is presently low so add on 20% more = 2100 kcals Therefore the prescribed diet will result in the following:
The suggested calorie intake is less than 50% of her needs; more importantly intake is considerably below BMR, and consequently the body perceives this as starvation. The body therefore switches to survival mode. Survival is a fundamental physiological response to a life-threatening situation and it is designed to ensure, at all costs, the continuation of life. Several changes occur so that whatever energy is available will last longer so that major organs (such as the brain) will be protected. Remember that the brain can only utilise carbohydrate for energy and can only access the glycogen stored in the liver – it does not have any stores of its own. All of this would be utilised on the first day of the diet in addition to consumed calories. Any glycogen in the muscle would also be used up.
Assume that this total amount of glycogen in both muscle and liver amounts to a total of about 250gms. Glycogen is stored in the body in a hydrated form (3gms of water for every 1gm of glycogen) and this weight of water would also be lost.
Total weight loss: 250g glycogen + 3 x 250g water = 1,000g = 1 kg = 2.21bs
Because the body is not being given the number of calories it needs, it slows everything down in an attempt to cope. In other words the BMR drops. This can be by as much as 20% and can occur within 24hrs, although it usually takes a little longer. So now calorie needs are only 20 per kg of body weight, which means that the calorie deficit created is gradually becoming less and less. On the second day the energy needs of the body may be a little less, but they are still more than the supply available. In particular, glucose for the brain is lacking and would need to be made by the liver. Glucose can be made quite easily by the body, but only by starting with amino acids. As dietary intake of protein is so low the body will have to obtain the amino acids it needs by breaking down its own stores. These are held in skeletal muscle. Muscle protein is also bound up with lots of water.
There are 4 g of water for every 1 g of protein. So even a small protein breakdown of 100g will mean a loss of lean body tissue amounting to five times this amount (in other words, 500 g or about 1 lb in weight).
Therefore 2 lbs of glycogen and 1 lb of lean tissue have already been lost in two days.
The body cannot sustain the continued loss of these amounts of lean tissue, hence one of the reasons for slowing everything down; however, protein breakdown remains fairly extensive in the early weeks of a low calorie diet until the brain adapts to using other sources of energy rather than unavailable glucose.
Certainly weight loss in the first week would be predominantly from lean body tissue and its associated water. Although fat stores are plentiful throughout this period they cannot easily be mobilised and used by the body.
There are several reasons for this.
Because fat is stored in a dehydrated form you would need to create a calorie deficit of 500 kcals a day, every day, to lose lib of fat per week or 3,500 kcals per week. However, remember that fat from body stores cannot make up the entire deficit created because a significant proportion of the calorie needs are from carbohydrate calories, not fat calories. Therefore, to lose just one pound of fat per week you would have to create a calorie deficit of around 750 kcals per day. A restriction of intake, similar to what we have already seen, would take most people below their BMR and therefore into physiological starvation.
During starvation the body will attempt to hold on to what reserves it has and would respond by:-
- Inhibiting the activity of enzymes that release and burn fat.
- Increasing the activity of fat storage.
Remember that the efficiency of fat burning decreases when carbohydrate is not abundantly available. As the diet continues weight loss per week will slow down partly to protect vital lean tissue, but also because of the physiological changes that occur as a result of starvation. It may well be that several weeks into the diet no further weight loss will occur – a plateau will have been reached, which means that the body has learned to adapt to the new situation, although at the high price; the body will be functioning less efficiently, subsequently putting your health in danger. The dieter is also at extreme risk of ketoacidosis due to the accumulation of ketone bodies (for full explanation of ketones and acidosis see page 24). It is also highly likely that throughout the whole of this time the dieter will be feeling fairly miserable, extremely lethargic, as well as suffering physical deprivation.
So what does she do? She may think that by reducing her calorie intake even further, to perhaps 750Kcals per day, she will ‘kick start’ her weight loss. This will create a new deficit and weight loss will indeed pick up again. Once again the body will have to learn to adapt as indeed it will and fairly soon weight loss will stop even on 750 kcals per day. Then what? 500 kcals? And then drop to 300 after the next round of adaptation? Fortunately, when plateau does occur, the most likely response is to start eating normally again, but because of the dramatic increase in calorie intake the body perceives it as a binge. Because of the physiological changes, what the body sees as extra calories will be very easily stored as fat.
Unfortunately, the weight that was lost whilst dieting was a mixture of fat and lean muscle tissue. When the weight goes back on again (this can take from a few months to a few years) it will be as stored fat.
Let us try to put ourselves in the place of the dieter. How would you feel if you had tried to lose weight, succeeded to some extent though not as much as you wanted but then over the next several months had put it all back on again, and perhaps even a little bit more? Guilty, upset, angry, miserable, worthless, unconfident, depressed, unloved, unlovable? There are probably a few more words you could add to this list but they all add up to the same thing- extremely low self esteem. What would you do? Give yourself a good ‘pull yourself together’ talking to and embark determinedly on another diet? So begins the merry-go round of yo-yo dieting. The net result of all this is that several years down the line and several diets later our dieter could well be two or three stones (15 to 20 kg) heavier than they were when they started and with 5 to 6% increase in their body fat. It is this well documented sequence of events that leads health professionals working in the field of weight management to estimate that 95% of all diets simply do not work. The key question then is what about the 5% that do work. What makes them different?
Consequences of consuming a low fat diet include:
- Decreased metabolic rate
- Decreased efficiency of fat mobilising and fat burning mechanisms
- Increased loss of lean muscle tissue
- Ketoacidosis
Dietary practices marketed to promote weight loss from a holistic perspective
- Very low fat diets – If you want to lose weight, you need to eat less calories per day than you have been eating (or do more exercise). When choosing a low fat diet, you also have to watch out for other types of foods such as sweets and sugary foods.
- High protein low carbohydrate diets – The high-protein low-carb diet was popular in the 1970’s, before saturated fat and heart disease became closely associated. Now, high-protein low-carb diets are once again popular due to the faster initial weight loss they can achieve. However, many dieticians preserve doubts about the long term health effects of these carb-restricted weight loss plans.
- Food combining – refers to the combination of foods which are compatible with each other in terms of digestive chemistry. Food combining is a basic component of optimal nutrition because it allows the body to digest and utilize the nutrients in our foods to their full extent.
- Meal replacement diets – meal replacement products must provide the recommended amount of nutrients needed for good health and their composition must conform to certain standards defined by a European Directive. According to this Directive – the guidelines for which are based on research looking at the nutritional needs of dieters – meal replacement products must contain between 200 and 400 calories, at least 25 percent protein and 23 vitamins and minerals. With regard to fibre, most products contain around 5-6g. Healthy eating guidelines recommend adults have 18g fibre daily and so two meal replacement products make a contribution to this. Most plans also recommend including fruit and vegetables as snacks and as part of your main meal. Ultimately, meal replacement products are not designed to be the only source of nutrition and contrary to popular belief, they are not the same as ‘very low calorie diets’, which generally provide less than 800 calories daily and are unsuitable for most of us.
- Fat burning and weight loss supplements – There are many companies out there who want to sell weight loss and fat burning supplements. Are they needed? Or would hard work and eating a healthy diet be the answer??? Check out the reviews for yourself on line.
- Elimination or limited food diets – Elimination diets are fine for those who may have an allergy and need to find out what they are allergic to, so eliminating foods helps. Individuals who suspect they are suffering from food intolerance or allergies are advised to consult a physician and dietician to confirm the condition.
- Rapid weight loss methods – Rapid weight loss is the goal of almost every dieter. Your physical appearance not only affects you personally but it can seriously affect what others think of you. Rapid weight loss takes a comprehensive approach that combines mind-set, exercise, and diet. The best place to begin is with healthy eating.
Safe and effective strategies for weight management
A well balanced exercise programme and nutrition programme are the answer to achieving weight management. A combination of both is more likely to result in log-term success than diet or exercise alone. There are NO miracle solutions.
The objectives of a healthy diet and exercise programme:
- Achieve a modest negative energy (calorie balance).
- Maintain or increase lean tissue.
- Reduce body fat percentage gradually.
- Avoid significant reductions in your BMR.
- Obtain the correct energy requirement.
- Achieve optimal intakes of vitamins and minerals.
MEASURING PROGRESS
To weigh or not to weigh?
It is not unusual for people who are trying to lose weight to use their bathroom scales as a measure of their progress. Unfortunately weight loss is not always synonymous with fat loss. A lot of weight loss can actually be from a loss in water, glycogen and lean body mass (muscle). Alternatively, if a person started an exercise programme such as cardio-vascular work and resistance training they certainly could lose fat yet not notice much of a change on the scales. This could be due to the fact that they are building muscle and losing fat at the same time. Therefore, as the scales only measure total mass they are not the best way to measure fat loss. This is not to say they shouldn’t be used, however, they are better used in conjunction with other methods.
Food diaries and journals
These can be extremely useful as a method of gaining an insight into how people are currently eating. However, as with all these methods it does have its drawbacks. People often forget to fill them in at the time of eating. When they remember to record the information, several hours may have passed and therefore the information will probably be inaccurate, as they may omit things they have eaten. Some people may also feel self conscious about what they are writing and so will be economical with the truth or write down an almost “perfect” diet. Nevertheless, if done properly it can be a valuable tool and it also helps to raise awareness about what and when they are eating.
Tape measures
These should ideally be used in conjunction with other body fat measurements. They are cheap, accessible and easy to use. It is important that a note is made of exactly where the measurements were taken from. Ideally, the same person should do the measuring. It is not recommended that the measurement is taken in less than six week increments.
24 Hour recall/weekly recall
What motivates an individual most is to feel a sense of achievement and to see changes taking place. Writing down how much food you have eaten within the last 24 hours or seven days can help the changing process.
Video/Dictaphone
These are other methods which can be used but be sure to explain these to the clients first so they are aware why you are administering them.
Skin callipers
Skin callipers can be a much more accurate method of measuring actual fat loss than the scales as they can determine between fat and lean muscle tissue. However, the measurements do need to be taken by someone experienced at using callipers to ensure accuracy. Callipers can also be quite intrusive, especially if a client feels self conscious, as they involve the subject having to be measured around the torso and the arms. The callipers themselves vary in accuracy as well. Cheap callipers often result in less accurate readings, with more expensive callipers providing a more exact reading. They are easy to carry and can be very useful with certain clients.
Using the Male Body Fat Data sheet convert the skinfold measurements in mm into a percentage fat figure, you will find that this client has ZZ.73% body fat.
To calculate lean body weight use the following formula:
Lean body weight = Body weight minus Fat weight Fat weight = Body weight x Fat%
Calculated as follows:
Lean body weight is sometimes referred to as the ‘fat Free Mass‘ (FFM)
If the ideal fat percentage for a 35-year-old male is 19%, you can now estimate how much this client needs to lose in order to achieve the ideal using the following formula:
This client would therefore have to loose 3.62kg of fat weight in order to achieve his ideal body fat percentage of
BODY MASS INDEX (BMI) – See fats
Bio-electrical impedance (body stat)
With this method, small electrodes are placed on the feet and hands and a very mild electrical current is passed from one to the other. An analysis is then conducted based on the speed of the current. This can be a quick and convenient method; however, its accuracy can vary. Often if an individual is dehydrated the reading can be misleading.
Other methods are available such as waist to hip ratios and food surveys. However, it is important to think carefully about what you are trying to measure and why. Very often it can be just as useful for a client to measure their progress against how their clothes are fitting or how they are feeling. Do they have more energy, feel more positive?
It is also important to be aware that if one particular method of measurement is chosen this can be detrimental to the client’s programme. The client can end up only focusing on the reduction of their body fat and not acknowledging all the other benefits they may be experiencing, such as reduced blood pressure, increased energy, stronger muscles and better posture. It is more advisable to encourage your clients to take a more holistic view of the benefits they are getting from their programme.
