Weight Loss: A New Perspective
I’m going to approach the issue of weight loss from a different perspective, so bear with me. I’m also going to be as honest as possible and put forward some hard truths. So here goes, I did warn you. 83% of people who achieve weight loss return to their pre-diet weight within 5 years…I’ll let that set in. Why don’t diets work? Why is it that 50% of the world population is predicted to be obese by 2025 (WHO 2013)? Lets look at: nutrition, exercise, psychology and the biochemistry of weight loss and maybe what then the secret…
All diets work. Why, because they put you into a negative energy balance. Eat fewer calories than your body needs and you loose weight. Simple? Maintaining weight loss is anything but simple. Longitudinal studies constantly show that only 35% of people maintain 5% of weight loss after one year, whilst only 17% of people maintain 10% of weight loss after one year. The statistics aren’t great reading.
Although all diets work, not all diets have the same effect on the biochemistry of our bodies. The type, the amount and the combination of food you eat all alter the digestion process and the associated hormones,basically your biochemistry. Simply, you alter your hunger based on your dietary intake. Many hormones influence appetite, to list a few: leptin, gremlin, PYY, GLP-1, glucagon and insulin. We understand that body composition influences appetite hormones, making it difficult for individuals who have greater levels of fat, as fat cells release leptin.
Theories exists like ‘set point theory’were a predetermined body weight is regulated by the hypothalamus which mediates systems such as appetite to help stay within a certain weight. What we do know is foods causing insulin spikes such as white bread/white pasta, potatoes, sugar, sugary drinks, confectionary etc. increase blood glucose levels, and it is this increase, followed by a drop in blood glucose levels, that increases appetite. Diets consisting of low glycemic index carbohydrates and high protein have the most significant weight loss results.
Why repeated dieting is doing more harm than good
Every time you loose weight you loose both fat mass and lean muscle mass. The only people who should ever be concerned with muscle mass decreases are professional endurance athletes and athletes in weight category sports. The amount of fat loss/muscle mass loss is dependent on the severity of the calorific deficit. Drop your calories by more than 500 kcal and your body will loose more muscle, so it needs less calories. The main issue I have with this 500 kcal rule, recommended by the World Health Organisation (WHO) is that 500 kcal is an absolute value, not a relative value, meaning decreasing intake from 2000 kcal to 1500 kcal (-25% of dietary intake) is completely different to someone who goes from 3000 kcal to 2500 kcal (-17% of dietary intake). This is why it’s best to cut dietary calories by 5-10% and not by an absolute value such as 500 kcal.
So lets get back to why repeated diets don’t work. Like I’ve mentioned previously, most people put weight back on after loosing it, but when you put weight back on it is in the form of fat (unless through weight training). Over time your lean muscle mass decreases, and this means your metabolic rate decreases, so you need less calories, and dieting becomes harder. Fat cells are also never actually lost; when putting on fat you are either increasing the size of your fat cells or making more fat cells. Genetics and weight dictate which is more likely. The more muscle you have the faster your metabolic rate, meaning the more calories you can consume. It has been shown to be healthier to exercise regularly and maintain a greater weight than it is to yoyo up and down. Over time you’re putting on more fat mass and loosing more muscle tissue. The most successful diets consist of high protein and low glycemic carbohydrate intakes. The increased protein will protect against muscle catabolism (loss), meaning more weight loss is fat, rather than muscle and will also make you feel fuller for longer. Avoid liquefied foods and high sugar foods that have fast digestion rates and result in blood glucose levels to rapidly change. Don’t reduce carbohydrates below 1.5 g.kg-1.BW-1 from your daily intake when dieting. Without carbohydrates, muscles catabolism increases, and you’ll struggle to exercise, its not beneficial in the long-term either.
Most diets follow a linear dietary intake where calories are gradually reduced over a period off time. Non-linear dieting involves alternating between days of high, medium and low intakes of carbohydrate. This requires very specific nutritional knowledge and understanding of periodization of both diet and training to design weekly intakes based around exercise and daily activities. We know that hypocaloric (low calorie) diets over prolonged periods, result in decreases in leptin levels, increasing appetite. So if dieting causes leptin to decrease then we need to increase calorie intake to prevent leptin and other appetite hormones from increasing appetite, hence the idea of non-linear dieting, preventing these changes in hormones. Since it is yet to be properly understood and clinically proven, I wouldn’t yet recommend it. It also requires a greater understanding of macronutrients and lots of planning, so isn’t yet the secret to success. I do however suspect that it may be the best method when done correctly. Don’t be surprised if you hear the term non-linear diet more often. Diets like the 5:2 and other intermittent fasting diets already follow a similar principle and are becoming increasingly popular and research is catching up on this method of dieting.
You can loose weight without exercising, but we need to exercise for psychological as well as and physiological benefits. Exercise causes dopamine and serotonin responses, affecting mood. High intensity and resistance exercise offers a protective mechanism against muscle loss, triggers protein synthesis, increasing muscle mass. Low intensity exercise induces the opposite effect and triggers a catabolic effect, decreasing muscle size and adapting muscles to use substrates of fat for energy, increasing efficiency. It makes very little sense to base your training around that of a cyclist or endurance runner, whose body composition is very different. Likewise to only do high intensity exercise is likely to result in injury and is potentially dangerous to overweight or unfit individuals.
So how should you be exercising for weight loss, but more importantly long term health?The current recommendations set by the world health organisation (WHO) for those who are 18-64 years of age are:
150 minutes of moderate-intensity aerobic exercise through the week or 75 minutes of vigorous-intensity aerobic activity through the week or an equivalent combination of moderate and vigorous intensity activity. For additional benefits increase to 300 minutes of moderate-intensity and 150 minutes of vigorous-intensity activity per week. Muscle strengthening activities should be done involving major muscle groups on two or more days a week (WHO 2013).
These recommendations are great and have been shown to have significant health benefits. Recent studies have found that it’s not just activity that is important, but the avoidance of inactivity. It makes no sense to do 60 minutes of moderate intensity cycling and then sit for 6 hours straight. It would be much better in those 7 hours to have been on your feet, doing daily tasks such as cleaning, walking, cooking etc. Being active like this will keep your metabolism higher.So a major change that you can make, without designing a new training plan, or even a new diet is simply to do more activities that decrease the time you spend being inactive.
High intensity training such as intervals, circuits, spinning, weight training and interval running elevate heart rate and increases metabolic rate. Not only will you burn more calories during exercise, you’ll continue to burn calories long after you have completed your session (24-48hrs). If your exercise is always based around low intensity, long duration cardiovascular training sessions, you’re most likely wasting your time. Simply, the higher the intensity you exercise, the more calories you burn. Low to moderate intensities over long durations offer great cardiovascular benefits, but is not ideal for weight loss. This doesn’t mean you should stop doing low-moderate exercise sessions; they should be balanced with high intensity sessions for maximum health and weight loss benefits.
So how can I change my psychological outlook? Your approach to a task is determined by two main variables: similar past experiences of a situation and your expectations of the task difficulty. We see dieting as difficult, as a result of having very little success with it. The issue for most people is that exercise and dieting is ‘hard’and requires a large amount of mental toughness. Exercise shouldn’t be hard; it should be enjoyable. It shouldn’t be viewed as exercise either, but as an enjoyable activity. You should actively look for opportunities to be active rather than inactive. This means seeing things that you may think of as chores as opportunities to be more active. The food you eat should be based on lifestyle decisions. Add nuts, seeds and wholegrain foods into to diet and reduce processed foods. Cook with fresh ingredients and cook with other people. We associate foods with emotions, another major issue, so make the cooking experience fun and regularly try new recipes. This doesn’t mean that there isn’t a time to enjoy foods we know are unhealthy for us, it just means that if you want to eat something you have control over it and can enjoy it at the right times.
Blaming your ‘bad genetics’is insulting to yourself and to others. Although studies have repeatedly demonstrated some people are ‘non responders’to exercise, what this actually means is some people are ‘less sensitive’. The body still adapts and weight loss is sill achieved. You may not have the genetics to have the same body composition or adapt to exercise in the same way as your favorite professional athlete, but this doesn’t mean that the reductions in blood pressure, resting heart rate and increases in VO2max are not significantly improving your health.
Weight loss is extremely difficult to achieve, especially to maintain. Viewing diet and exercise as an instant means of reaching your goals, is not the right approach. Expecting that by reaching you target weight, it willsuddenly make you happy and that you’ll be able to easily maintain it without being hungry; is both unrealistic and likely to result in failure. These are hard hitting truths, but until you view exercise and diet as lifestyle choices, you’re likely to be forever stuck in an undesirable weight loss/weight gain, yoyo state. So my advice, as we approach a time of year associated with new goals, new aspirations and a new you, is to choose the journey. Make changes slowly to your diet and exercise habits; don’t change everything at once. Eat more protein and consume low glycemic carbohydrates. Add nuts, seeds and wholegrain foods to your diet. A new year brings forth new opportunities, so write down all the activities and foods you enjoy and make small changes. Try a new sport or activity; find a new person to exercise with or try and new recipe. Look for new habits that will fit your new lifestyle choices, like going to a cookery class or joining a weekend sports team. Make these activities fun and make it your lifestyle. Don’t be focused on the number on the scales, but how you feel. Try to monitor changes with a tape measure, a much healthier method of monitoring change. Combine diet and activity together and view them as components of your day and look forward to the food that you cook and the activities you engage in, and that really is the secret.
Cook with fresh ingredients and find activities you enjoy. Happy New Year.
(Notes on the Author – Danny Foster is an avid runner and nutrition expert currently studying sport and exercise science at Sheffield Hallam University. He works in our Sheffield Decathlon branch and currently works as an expert sports adviser, ensuring each running/nutrition customer leaves the store kitted out with everything they need for their next race. Are you interested in a job that lets you pursue your passion? Why not scoot over to our careers site and discover the many positions available – http://www.decathlon-jobs.co.uk/ )