What does ‘lose weight’ actually mean?
Physiologically speaking, to lose weight you must burn more calories (through physical activity) than you eat or drink. Basic body functions (e.g. breathing, nerve function, manufacturing cells, blood circulation and maintaining body temperature) use 50-70% of your calories/energy. The rate at which your body uses calories/energy for basic body functions at rest is called the Basal Metabolic Rate (BMR).
Additional factors that strongly determine your BMR include your genes, age, gender and body composition. Therefore, much of your energy use is predetermined. However, the amount of energy you burn each day also depends on how much exercise you do (intensity, type and duration).
Why is it harder to lose weight than it is to gain it?
I think it’s important to note that the biology of weight loss, and weight maintenance, is a complex process. There are so many factors that contribute to overweight and obesity such as diet, inactivity, genetics, smoking, motivation, alcohol consumption, stress, poor sleep hygiene, occupation, environment, hormone imbalance to name a few.
If you are struggling to lose weight, it’s important to rule out any underlying causes first and foremost. There could be a medical reason for your struggle such as a chronic health condition such as cardiovascular disease or type 2 diabetes, or a hormone imbalance such as your thyroid, sex hormones, insulin or cortisol. In some of these cases, it won’t matter how much physical activity you do, you will continue to struggle to lose the weight until the cause is rectified.
Other factors that contribute to difficulties losing weight include regular yo-yo dieting, mindless eating, sedentary lifestyle and slowing metabolism that comes with age. These factors predominately influence your hormone function, which plays a major role in your body’s ability to lose weight. For example, weight cycling or yo-yo dieting can change your physiology. A reason for this is that through constant dieting, your hunger hormone, ghrelin increases, and your fullness hormone, leptin decreases. As a result, you will feel hungrier and less satiated every time you eat. Also, this type of eating/dieting makes you lose muscle mass and is replaced with fat as you regain weight. Since muscle burns many more calories than fat, your metabolism slows down further as a result.
How long does it take for a person to lose one kilogram who has started exercising 3 times a week and eating a healthier diet?
There is no calculation for this as every individual is different and how their body responds to exercise will differ as well. If an individual is significantly over weight and has more weight to lose than the average person who wants to lose 5kg, they might lose more weight, more quickly. However, this weight loss may be a combination of fluid loss and fat loss.
For someone who has started exercising three times a week and eating a healthier diet, they may expect to lose one kilogram in one and a half to two weeks. This is also dependent on the type of exercise they are performing and the duration and intensity of their training.
A guide to follow for safe and sustainable weight loss is to aim for 0.5 – 1kg per week. In order to lose one kilogram per week, you would need to burn and/or reduce your dietary intake by approximately 1,000 calories per day. Having said this, it is also important that you create as much food variety as possible so you do not put yourself at risk of malnutrition or nutrient deficiencies.
Tips to help you lose weight in a healthy way?
Some simple tips for a healthy approach to weight loss include:
- Avoid yo-yo dieting or weight cycling – crash dieting is a short-term solution that will increase your body fat levels in the long term due your body lowering its metabolic rate as a result.
- Avoid fad diets – same reason as above.
- Don’t skip meals – if you do, you are more likely to eat more when you do eat, and this may lead to a larger stomach capacity.
- Exercise regularly – aim for at least five days per week and make sure it is a combination of resistance (weight) training and cardiovascular training for best results.
- Cut down on the carbs – refined carbohydrates such as cake, biscuits, cookies, muffins, chips, cupcakes, soft drink, fruit juice, and most supermarket breads will make you store fat if not burned off.
- Be cautious of portion size of main meals and snacks – always eat to 80% full before returning for seconds.
- Keep tempting foods/indulgent foods out of the house.
- Don’t drink your calories – avoid beverages that contain empty calories and don’t fill you up such as soft drinks, large fruit juices, energy drinks.
- Control emotional eating – the brain is programmed to crave high sugar and fat foods when we experience emotional stress.
- Increase vegetable intake – most non-starchy veg are low in calories and high in fibre, which means they will fill you up and keep your waist in check.
- Get a good night’s sleep – optimise your sleep hygiene and routine and aim for 7-8 hours per night.
- Make water your choice of drink – water can help boost metabolism as well as keeping you well hydrated for optimal energy and performance.