With the nation getting ever fatter and the burden this will have on our health and economy, the government and health care professionals alike are urging us to lose weight and become more active. But there are so many different diet books and weight loss programmes on the market and so much conflicting information in the press that it can sometimes be quite confusing about what to do.
From an evolutionary perspective humans are designed to be lean, muscular and highly active. Just look at animals in their natural environment where there is no human interaction – you very rarely see overweight animals (except those that store fat before hibernation) and you never see obese animals.
Alarmingly the House of Commons Health Committee Report on Obesity estimated the economic cost to the nation of people being overweight and obese to be 6.6 – 7.4 billion. At a time where our economic future looks bleak we need to realise that it is no longer acceptable to let ourselves become overweight or obese. Nor is it acceptable to put the responsibility of our health care on to others such as the government and the National Health Service (NHS). We need to take responsibility for the decisions we make in our lives including the decisions that affect our health. Of course there are genetic and environmental factors that contribute to our body shape and our health – but no one gets obese just from having “bad” genes. People only get overweight or obese from what they chose to eat on a daily basis and from lack of exercise.
What’s wrong with being a little bit fat?
Fat is not just an unsightly inert substance that sits on your love handles or muffin top. It does not just serve as a reservoir of energy to be called upon when needed for energy. Fat is metabolic tissue that can cause all manner of things to happen in your body. Fat cells release the hormone leptin that serves as a signal for energy sufficiency. Leptin levels decline with calorie restriction and weight loss and rise above normal levels with weight gain and obesity. Obesity can lead to leptin resistance, much like insulin resistance whereby leptin can no longer tell the brain that we are full. This may lead to overeating. Leptin also interacts with other hormones such as stress and thyroid hormones, it modulates the immune system and aids bone formation. Disrupted leptin levels through obesity can affect how these hormones work, affect the immune system and alter bone formation.
Fat cells become infiltrated with high levels of immune cells that release inflammatory chemicals disrupting the uptake of sugar and burning of fat in liver cells contributing to insulin resistance, the onset of type 2 diabetes and narrowing arteries. Fat cells release chemicals that clot your blood, increase your blood pressure and convert inactive stress hormones into active stress hormones and contribute to conditions such as hypertension, stroke, cardiovascular disease and PCOS.
Fat cells also convert male hormones to female hormones. This may be a good thing for post-menopausal women as this provides a source of oestrogen, but this is not good for pre-menopausal women who presumably have normal oestrogen levels, nor is it good for men, making them more feminine. There are also links between excess oestrogen and conditions such as fibroids, endometriosis, breast and ovarian cancer.
How do you know if you are at risk?
There are several ways to ascertain your weight and body composition (fat mass compared to muscle tissue) and whether you are at risk from being overweight and at risk from the associated health conditions. These same measurements can be employed to monitor your progress on a weight loss programme.
Standing on the scales is the first port of call for most people. Although measuring your weight is good practice you need to remember the scales only tell you your gravitational attraction to the earth in stones, pounds or kilos, they do not tell you anything about your body composition or about your regional fat distribution. To get a true body weight and chart your weight loss only weight yourself once a week, on the same day, at the same time, on the same pair of scales after emptying your bladder and bowels and whilst naked. Deviating from this advice could give you false and highly variable readings.
Body mass index (BMI) is another measurement tool used to determine whether you are under, over or of normal weight. BMI, a calculation of your bodyweight in kilos divided by height in meters squared,is generally a reliable system, but it is not without criticism, for example a male with a lot of muscle mass may actually be of “normal” weight and body fat for his height but is classified as being overweight, whereas someone who has very little muscle mass but some additional fat (thus being technically termed a skinny fat) may show up in the normal band. Additionally, BMI does not tell you anything about other important markers for health and disease such as waist circumference, body fat percentage or regional body fat storage.
Waist circumference (WC) and waist to hip ratios (WHR) are two good measures employed by health professionals as a simple and effective tool to identify obesity and disease risk. Research has demonstrated that men with a normal BMI that had a 40 inch waist were twice as likely to die as men with a 34 inch waist and women with a normal BMI that had a 35 inch waist were 79% more likely to die than women with a 29 inch waist. Waist circumference can be measured with a standard tape measure and should be measured around (what should be) the narrowest point of the waist between the rib cage and hips. Clearly a lower score is better.
Numerous studies have demonstrated the metabolic complications and disease risk of having a high waist to hip ratio (i.e. a greater measurement in inches or centimetres at what should be the narrowest point around the waist compared to the widest point of the hips). The true healthy waist to hip ratio may vary a little depending on which studies you read, but could be classified as less than 0.85 in women and less than 1 in men (i.e. women should have a much narrower waist than hips, and men should have a slightly narrower waist than hips). Again this is easily measured with a tape measure.
Knowing your body fat percentage is also important to assess your risk of disease and chart your weight loss progress, clearly the more overweight or obese you are the more body fat you will have. But “thin” people can also have excess body fat.
Body fat measurement
The most accurate ways to measure body fat is by using imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI) orDual-energy X-ray absorbtiometry (DEXA) scans. However these methods are expensive, time consuming and impractical for clinicians such as doctors and nutritional therapists to use in clinic.
Other methods includethe Bod pod, underwater weighing, bioelectrical impedance (BI) and using skin fold callipers (SFC).
The Bodpod is a chamber you sit in for 5 minutes that uses body weight and air displacement plethysmography to determining body fat and is a fairly accurate and reliable system to use, however the pods are quite expensive which might make their use limited in clinical practice.
Underwater weighing is a process where a person is lowered into a tank full of water until all body parts are emerged. The person must then remain still underwater while a weight is recorded. This procedure is repeated several times to get a dependable underwater weight from which body fat is calculated. This technique is quite unpractical for a clinical setting.
BI is a scientifically validated technique used for measuring body fat that is becoming increasingly popular in hospitals, health centres and gyms, with many different devices on the market for home and professional use. The BI device sends an electric impulse through the body using the time elapsed from when the signal passes through your body and back to the device to estimate body fat percentage and lean muscle mass. There are some criticisms of these devices – that they can give a false reading depending on how under or hyper hydrated you are. Nor does the BI device give you any information on regional fat stores and has to be used in conjunction with WC and or WHR to establish this. If combined with other methods BI could be useful in clinical practice.
Using SFC is another reliable way to measure skin fold thickness and bodyfat and can be used to chart regional body fat reduction. Sites such as the triceps, subscapula, suprailiac, umbilicus, mid-axillary, and thigh are commonly used in research studies that can be used to calculate body fat. Conversely you can tally the sum of the sites and use that number to chart whether you are losing body fat. Criticisms include that there can be problems with intra-tester and inter-tested variability and that the equations used to calculate a body fat percentage can be inaccurate. However using skin fold callipers are a quick and reliable method in a skilled pair of hands and very suited to a clinical environment.
Once you have ascertained your weight, WC, WHR, body fat percentage and information on your regional fat distribution, it is a good idea to re-test once a week during your weight loss programme to chart your progress, as with weighing yourself conduct these tests once a week, on the same day, at roughly the same time of day, after emptying bowels and bladder whilst naked. Make sure you use the same equipment each time for consistency. Now you have started collecting your weight loss data, what do you do?
Weight loss diets
Deciding the best way to lose weight can often be a little tricky – the basic premise of taking in less calories and burning more calories in the form of exercise holds true but there are a couple of caveats. The Department of Health recommends a calorie intake of 1940 calories per day for women and 2550 for men and there have been calls to increase these guidelines by another 400-500 calories. However these guidelines may be too high or people just do not follow them and eat too many calories considering the number of people that are overweight in the UK. The type of calories consumed can also have an impact on weight gain / loss, for example 1g of carbohydrate and 1g of protein both contain 4 calories, and 1g of fat contains 9 calories.
Research from Harvard School of Public Health investigated what would happen to people who eat a 1500-calorie low fat diet (1800 calories for men) compared to an 1800-calorie low carb diet (2100 calorie for men). The findings were that the higher calorie low carb dieters lost more weight than the lower calorie low fat dieters. A third group was studied who consumed a 1500-calorie (1800 calories for men) low carb diet and these people lost the most weight.
Another study looked at people on a calorie matched low carbohydrate or low fat diet, the food ratios were as follows:
- Low-fat: 60:20:20 (carbohydrate:fat:protein)
- Lower-carb: 45:35:20 (carbohydrate:fat:protein)
Women eating the low carb diet lost an average of 3.4 lbs (1.5 kg) more than the women eating the low fat diet (an average of 19.6 lbs v 16.2 lbs). Even the low carb diet was still fairly high in carbohydrates and could have been reduced further to maximise weight loss.
Reducing carbohydrate usually means an increase in protein and fat. But most people fear eating too much fat because they think it will make them fat (remember 1g of fat contains 9 calories) and get advised against eating too much protein as it damages the kidneys and affects bone health. Both of these points are contentious issues and should be discussed in a separate article but suffice to say that a higher protein diet(43% carbohydrate, 33% protein and 22% fat) was more favourable in terms of weight loss when compared with resistance exercise to a conventional diet (53% carbohydrate, 19% protein and 26% fat) and exercise.Furthermore the prestigious Journal of the American Medical Associationreported that a low glycemic load (GL) diet helps to reduce insulin, triglycerides and aids weight loss in overweight and obese people.
Taking in too few calories can be as detrimental as eating too many. Restricting calorie intake can cause you to lose muscle and bone density and can affect import hormone function such as the thyroid hormones. Having said that calorie guidelines may be set too high and by reducing calories to a lower but still sufficient level can aid weight loss. In order to work this out Jonny Bowden describes multiplying your target weight in pounds by 10 to get the rough number of daily calories you need to consume. For example if you want to be 150 pounds (68kg) eat roughly 1500 calories a day with only a low proportion of these calories coming from carbohydrates (40% carbohydrate, 30% protein and 30% fat).
How do you do this?
For some of you working out calories and ratios of food can be too complicated, so how do you work out a good weight loss diet? For breakfast simply eat some eggs, such as scrambled eggs on toast or an omelette, eat some plain yoghurt with berries or eat some muesli or porridge.
Aim to eat 1 portion of animal protein at lunch and dinner such as a fillet of fish, a chicken breast, a home made turkey of beef burger, this will give you between 200-300g of protein which is sufficient. If you are vegetarian you will need to think about eating some eggs, or fish or tofu and combine some whole grains with beans, legumes and nuts. Aim to eat lots of non-starchy vegetables such as broccoli, cabbage, onions, asparagus, but few if any starchy vegetables such as potatoes, sweet potato and corn. If you like some grains eat small servings of brown rice or quinoa.
Use smaller plates and divide your plate into one half and 2 quarters. The half should be full of non-starch vegetables, a quarter should be full of a good protein source such as fish or chicken and a quarter can be full of a small serving of sweet potato, quinoa or beans.
For snacks aim to eat a couple pieces of low GL fruit per day such as apples, pears, plums or berries and also eat some nuts, seeds, beans and legumes, but ditch the bread, pastry and other starchy grains in snacks.
Supplements to aid weight loss
There are many different herbs and supplements on the market that claim to improve weight loss but which ones actually work?
Vitamin D is receiving a lot of attention recently with research linking deficiency to all manner of conditions including autoimmune disorders, depression and poor muscle function. Some recent studies have found that women of various ages who are vitamin D deficient are more likely to have a higher BMI and waist circumference. Thus there is a good argument to support the use of a daily vitamin D supplement not just for general health but to prevent getting fat. More research is needed to explore whether vitamin D actually increases weight loss.
A nutrient called carnitine is required for fatty acids to get in to the fat burning machinery of the cells, therefore carnitine has become a popular supplement on the weight loss market. Research from the Universityof Rostock in Germany demonstrated that 3g of carnitine a day led to the body burning slightly more fat in overweight adults. However the research remains mixed as to carnitines’ beneficial effects.
Green tea contains a catechin called epigallocatechin gallate (EGCG); 300mg of this extract has been shown to significantly reduce weight, waist size and fat mass in overweight men. Another study published in the American Journal of Clinical Nutrition domonstrated that green tea containing 350 mg of EGCG increased fat metabolsim after exercise and improved insulin sensitivity. Green tea also contains caffeine which has been shown to improve weight, fat mass, and waist circumference and when taken together, green tea and caffeine can significantly improve fat burning and weight management.
Conjugated linoleic acid (CLA) is a type of fat found in the animal fat we eat, however the content of CLA in our meat and dairy is altered through modern day farming methods. The Universityof Wisconsin in America conducted two meta-analyses on trials researching CLA and weight loss and found CLA increases fat free body mass and that a dose of 3.2g a day was effective at producing a modest loss of body fat in humans. Therefore taking 3g a day of CLA would be good to add to your weight loss supplement stack.
Example daily plan
Breakfast Spinach, tomato and mushroom omelette made with 2 eggs and a little olive oil, a cup of green tea and a handful of berries.
Mid morning snack (optional)
10-15 almonds and an apple
Sip on 500ml of water
Lunch 100g fillet of salmon with a large mixed leaf salad, and any salad fillers such as some olives, tomato, cucumber, artichoke, pine nuts or toasted seeds or even a small mixed bean salad. Add a twist of salt and pepper and a drizzle of olive oil
Sip on 500ml of water
Mid afternoon snack (optional)
1 carrot crudit with 20-30g of hummus
Sip on 500ml of water
Dinner 1 average chicken breast with steamed or roasted vegetables, a small side of quinoa and small knob of butter or a drizzle of olive oil on the vegetables.
Sip on 250ml of water
- 2000IU of vitamin D
- 350mg of green tea extract EGCG
- 3g carnitine
- 3g of CLA