A new year is often the time to focus on goals for the year ahead with many of us making a commitment to shift those unwanted Christmas pounds to improve body composition while also increasing training volume or intensity. In my experience as a Dietitian I often find that at this time of year the media interest in weight loss and promoting the ‘next best miracle diet’ can often lead to restrictive diets which can negatively impact on health and performance. As a Sports Dietitian I do not recommend that athletes diet but make small changes to their nutrition to achieve slow, gradual weight loss that does not impact on training and performance.
Why is Dieting not appropriate for athletes?
The food we eat provides more than just calories; it also provides essential energy for working muscles and nutrients for health and well-being. Energy in the form of the food we eat is required to fuel training but also drives adaptations following exercise that promote recovery and improve performance. We also get key vitamins and minerals from our diet that support bone health and immunity such as Calcium, Magnesium, Iron and B vitamins. By following restrictive diets you run the risk of energy deficiency which can impact on the quality of your training and recovery. Many popular diets also restrict or eliminate food groups which can result in nutritional deficiencies. Training places considerable strain on the body and energy demands must be met to keep you healthy and performing at your best, as a result diets are not advisable and can also make you susceptible to illness, infection and injury. Over recent years in endurance sport particularly there has been considerable interest in the High fat low carbohydrate (HFLC) diet with claims that it supports weight loss and performance. Recent research by Louise Burke and colleagues (2017) demonstrated that these claims however are unfounded. Burke and colleagues studied two groups of elite race walkers, one group consumed a HFLC diet and the other group a normal diet comprising 50% energy from carbohydrate. Results showed that performance was reduced in the group consuming the HFLC diet. The reason for this can be attributed to the fact that when exercising at a high intensity (Vo2 max > 60%) the body uses carbohydrate to fuel muscular contraction (Van loon 2001). Subsequently following a HFLC diet means that there is less available fuel to support muscular contraction which can result in a negative impact on performance – not a good situation when that sprint finish is required or that hill climb!
Don’t rely on the numbers on the scale!
Rapid weight loss can reduce the numbers on the scale but although reducing fat mass can be an advantage losing lean muscle mass is not. Lean muscle mass is metabolically active tissue that enables you to burn energy efficiently and supports strength and performance. A key goal therefore for any athlete with achieving healthy weight loss is to reduce fat mass but preserve lean muscle mass which is why understanding the importance of sensible weight loss is so important. For this reason it is recommended that you seek support with monitoring weight loss ideally through having regular body composition measurements undertaken such as 8 site skin-fold measurements that monitor lean muscle mass and fat-free mass.
What is sensible Weight loss?
Sensible weight loss does not involve dieting or restrictive eating but making small sustainable changes to dietary intake that will support slow gradual weight loss without impacting on performance. It is also important to consider that on some days you will need more energy than on other days depending on the training undertaken so energy and food intake should be adjusted to meet training needs and should not be static. The ACSM (2017) recommend aiming to lose no more than 1-2 lb/ week; a faster rate of weight loss can result in losses of lean muscle mass which can reduce performance. This can be achieved by estimating daily energy intake and reducing this by approx 250-500kcal per day. At the same time you should ensure that you maintain an adequate protein intake to preserve lean muscle mass – protein rich foods include meat, fish, dairy foods such as cheese, milk and yoghurt and plant-based proteins such as quinoa, beans, lentils and tofu.
A Sports Dietitian’s Top tips for Healthy weight loss!
- Assess you Energy Requirements and Energy Intake. By knowing how much energy your body needs and how much energy you are consuming on a day-to-day basis you can build in a factor for weight loss (a reduction of 250-500 kcal/ day will achieve 1-2lb weight loss per week)
- Remove temptation – following Christmas it’s a good time to clear the cupboards of tempting snacks that might be high in fat and sugar such as biscuits, cakes and crisps. Fill your cupboards with healthy alternatives such as fruit, yoghurt, rice cakes, cereal bars, malt loaf.
- Be careful of foods that claim to be healthy for example a 100g portion of breakfast Granola can contain 22g of sugar and 12g fat!
- Replace butter with an olive based spread which is better for your heart. A small pat of butter is as much as 100kcal. Avoid using saturated fat such as coconut oil – coconut oil is higher in saturated fat than lard and is not advisable for a healthy heart. Use an olive oil/rapeseed oil in cooking and use sparingly ideally choose spray oil as every tbsp. of oil is approx. 100kcal.
- Avoid skipping meals, the key to effective weight loss is regular meals to prevent hunger and maintain blood glucose levels. Research has consistently shown that people who eat regularly and avoid skipping meals achieve more sustainable weight loss.
- If you crave sweet foods after your main meal have some tinned fruit with a tbsp. of Greek yoghurt. Tinned, fresh and frozen fruit are all equally as nutritious but choose fruit in natural juice rather than syrup.
- Try to include colour at each meal in the form of fruit and vegetables which are high in nutrients, vitamins and fill you up preventing you from snacking later in the day. e.g. have fruit with your breakfast for example blueberries with your porridge, a salad with your lunch e.g. watercress, spinach and rocket salad sprinkled with pumpkin seeds and pomegranates and vegetables with your evening meal or tinned fruit as a pudding.
- If you do need to snack which is important if you are training choose healthier snacks such as rice cakes and humus, fruit and yoghurt, malt loaf, a cereal bar, small bowl of cereal (40g) with skimmed milk, slice of rye bread with peanut butter.
- Be mindful of ‘natural’ or ‘healthy’ bars – despite being promoted as being healthy some of these can be as high as 240kcal and 12g of fat especially those that are made with nuts/ chocolate etc.
- Plan your meals and nutrition. Having a training plan is great but it’s also a good idea to consider what your weekly meal plan will look like – this will ensure you have a structure and stay on track. If you know you ae going to be working away from home or on a long ride with a café stop plan what you will eat – being prepared is being in control of your nutrition.
- Fuel appropriately if you are exercising < 90mins you do not need to fuel whereas if you are exercising > 90mins you need to re-fuel. The amount of carbohydrate required depends on the duration and intensity of the activity you are undertaking. Many athletes over/ under fuel, seeking guidance on appropriate fuelling is essential for performance.
- Recover sensibly – following exercise it is important to recover fully with approx 1g/kg carbohydrate and 20-30g protein. This will replenish your fuel stores and help to drive the adaptations post exercise that improve performance such as muscle protein synthesis. Many athletes however over-use protein supplements such as whey. Although convenient i.e. if your meal is delayed by 60-90mins post exercise, if your next meal is within this timeframe taking additional supplementation is not required and only adds additional calories and fat to your daily energy intake.
ACSM (2017) Nutrition And Athletic performance. Medicine and Science In Sport and Exercise. Volume 38 Issue 3 543-568
Burke, LM. Ross, M. Garvican-Lewis, LA. Welvaert, M. Heikura, IA. Forbes SG. Mirtschin, JG. Cato LE, Strobel, N. Sharma, AP. Hawley. JA. (2017). Low carbohydrate, high fat diet impairs exercise economy and negates the performance benefit from intensified training in elite race walkers. The Journal Of Physiology. Volume 595 Issue 9 P2785-2807.
Van Loon, LJ. Greenhaff, PL. Constantin-Teodosiu D. Saris, WH. Wagenmakers, AJ. (2001) The Effects of Increasing Exercise Intensity on muscle fuel utilisation in humans. The Journal Of Physiology. 536: 295-304