Firstly, you need to determine what your ideal weight is for you. Working with a qualified fitness professional to measure your body fat is the best approach, so that you can determine your existing body composition using more than a generic BMI measurement. Once you understand your body fat, you can better understand how much fat you have to lose.
For athletes, competing at the right weight is especially important and you need to take into account your sport, build and ideal body composition.
How long should weight loss take?
You should realistically aim to lose 0.5g per week, any more will likely be water loss or worse still muscle loss which you want to avoid for loss of energy or power for athletes (1). You need sufficient energy for exercise, so too much food restriction during heavy training periods will impede your training and compromise your performance gains (1).
Try to lose your weight steadily through healthy clean eating and regular exercise (1). Don’t follow any crash diets as not only will they impede your training program, but they will also cause the weight to be regained once you return to regular eating. Your body needs a wide range of nutrients, especially if you exercise, so restricting food intake too dramatically can be disastrous to your health.
Energy In, Energy Out
Weight loss is all about energy in and energy out. If you are eating more than you are expending each day, your energy balance is positive and you will gain weight. If it’s neutral you’re eating enough to perfectly fuel your energy needs. To lose weight your energy balance needs to be negative. To lose half a kilogram of fat per week, this equates to approximately 3500 calories of negative energy balance per week, or around 500 calories per day, depending on your starting weight and exercise levels.
This means you will need to work out how much energy your body needs just to exist. There are many calculators available online that will give you a pretty good estimate of your energy needs through inputs such as age, weight and height. They’re not precise but they’re a pretty good place to start. Next you need to keep track of both your exercise and food intake.
There are apps which allow you to track your food intake, or working with a qualified nutritionist or dietician will help you to estimate your energy intake will make life easier.
Either way, once you start logging food you become very aware very quickly of your food choices, portion sizes and in particular your snacking habits. Keeping track of your daily exercise and the energy that it burns, will allow you to get a fairly good idea of what your food consumption should be to hit the daily deficit of 500 calories.
Eat less or Exercise more?
Don’t just aim to lose weight through eating less. Your body best burns fat during low intensity workouts. Aim for long slow workouts to increase your energy expenditure and increase your fat burn (1). Don’t be fooled by weight loss resulting from dehydration during heavy workouts, ensure you are staying sufficiently hydrated (1).
A good way to overhaul your diet and eat healthier is by following these tips:
- Aim for a diet with 20% of your energy from carbohydrates on light training days to reduce your insulin resistance (2). When you eat carbs, your pancreas produces insulin. Insulin prevents your fall cells from breaking down fat for fuel, it helps excess glucose turn into fat, and tells your liver to absorb as much glucose as possible for later use.
- Reduce snacking and fast for short periods to improve your body’s ability to burn fat as well as carbohydrate
- Get your carbohydrates from a big variety of fresh fruits, vegetables, dairy and wholegrains, not baked goods, pasta, rice, bread or foods that we would consider nutrient poor ‘fillers’. This is also great for gut health which will assist in weight loss.
- Avoid gluten to improve your digestion and reduce inflammation. Stick to unrefined non gluten whole grains such as quinoa, millet, oats, amaranth, buckwheat and sorghum
- Don’t rely on supplements! Eat the rainbow and lots of antioxidants. Bright fresh fruit and vegetables are often high in nutrients which will reduce inflammation, including your stomach lining, helping your body to absorb nutrients and run more efficiently.
- Eat plenty of fibre but introduce it slowly. It leaves you feeling fuller, helps with healthy bowel movements and acts as a prebiotic, allowing your healthy gut bacterial to flourish
- Make every bite count, ensure it’s full of as many nutrients as possible, and avoid processed foods, especially those high in preservatives
- Avoid added sugars and stick to 6 teaspoons of added sugars per day. This includes honey, yoghurts, sweetened foods, juices, smoothies, processed snacks, baked goods, basically anything other than fruit, vegetables and milk.
- Alcohol is full of empty calories and doesn’t need to be absorbed, it goes straight into your bloodstream. It can lead to higher consumption of energy dense and nutrient poor foods, and slows your metabolism as it overworks your liver. So ensure you have at least 3 alcohol free nights per week, and stick low sugar alcohol such as dry white wine, red wine, or white spirits with sugar free mixers.
- Avoid starchy foods such as potato. These are high in natural sugars and shouldn’t be included in your target serves of vegetables per day.
- Eat good amounts of protein when you are eating low carbohydrate volumes and exercising. Your body will be looking for alternate fuels with insufficient carb stores, and may break down protein stores (muscle) for energy. You don’t want to lose muscle when you lose weight. Protein will also make you feel fuller for longer. Spread your protein intake across the day, by aiming for equal amounts at breakfast lunch and dinner. Any more than 30g in one meal can’t be absorbed or stored by the body and will be wasted.
- Reduce saturated and trans fats from your diet – anything fried or processed. Eat plenty of healthy fats, omega 3, which are essential to reduce inflammation and build healthy membranes, including your brain and nervous system. Omega 3 fats can be found in fatty fish such as salmon and tuna, in chia seeds, eggs, dairy and lean meat.
- Garthe, Ina, et al. “Effect of two different weight-loss rates on body composition and strength and power-related performance in elite athletes.” International Journal of Sport Nutrition andExercise Metabolism2 (2011): 97.
- Bazzano LA, Hu T, Reynolds K, Yao L, Bunol C, Liu Y, et al. Effects of Low-Carbohydrate and Low-Fat Diets: A Randomized Trial. Ann Intern Med. 2014;161:309-318. doi:10.7326/M14-0180