It’s that time of year when everyone starts looking forward to warmer days and sunshine, and of course more time on the bike. It’s also the time when many cyclists think about losing those winter kilos that went on watching Le Tour, whilst your bike got lonely in the corner.

Weight loss for athletes (an non-athletes) remains a minefield of fact, fiction, best sellers and diet plans. So what’s the basic science that underpins weight loss, what’s different for athletes, and what are some practical tips for cyclists wanting to lose weight?

Firstly I want to start by considering the two meal plans below. Have a close look then answer this question: which would be more effective if you were trying to lose weight?

More on this later…

Nutrition Basics

Apologies if you know this already but it’s important to first understand a few basics before we go further. Our bodies produce energy from four nutrients (or fuel sources if you like) – fat, carbohydrate, protein and alcohol. Energy is measured in kilojoules or calories – generally speaking one gram of carbs and protein provide 4 calories each, a gram of alcohol 7 calories and a gram of fat 9 calories. The body produces energy for metabolism (the bodily functions that keep you alive), thermogenesis (heat production), and for muscle contractions (to produce movement).

Energy balance compares the amount of energy you’ve eaten to the amount you’ve used. Energy balance is either positive (more eaten than used), neutral (equal amounts) or negative (less eaten than used).

In positive energy balance you’re eating more than you need. Excess fat is stored as body fat. Excess carbohydrate is stored in the muscles and liver as glycogen (a form of carbohydrate). The one about avoiding carbs at night because it’ll convert to fat is incorrect – if it were true then how could you carb load? Excess protein and alcohol aren’t stored; instead they’re preferentially used as an energy source whilst sparing carbs and fat.

Overall a positive energy balance causes weight gain, negative energy balance weight loss and a neutral energy balance a stable weight. Almost a century of research has failed to prove otherwise, and every diet known to man works only when it achieves a negative energy balance.

So coming back to my question, did you choose Meal Plan A or B for weight loss? The correct answer is the one that’s lowest in energy. That’s Meal Plan B, which contains about 400 calories less and demonstrates an important point:

Eating for health and eating for weight loss are not necessarily the same thing

I’m not suggesting that you should eat Meal Plan B. As you’ll see below it contains much more saturated fat and much less calcium and iron. But never assume healthy eating guarantees weight loss. You still need to achieve a negative energy balance regardless of the make up of the diet.

Does the type of calories matter?

Is it as simple as manipulating energy balance to lose weight? Research suggests that negative energy balance is the only thing that matters for total weight loss. The largest study on the topic was published in 2009, comparing 811 overweight people randomised to one of four diets:

  • - Low fat, moderate protein, high carb
  • - Low fat, high protein, moderate-high carb
  • - High fat, average protein, moderate carb
  • - High fat, high protein, low carb

 

After 6 months, then again at 2 years there was no difference in weight loss between the groups.

This finding is fairly consistent when looking at total weight loss. However it’s a different story if you want to preserve muscle and focus just on body fat loss. Athletes can obsess about reducing kilos on the scales. But be careful what you wish for – a large weight loss may improve your power/weight ratio and climbing prowess, but if you lose muscle your total power (hence sprinting and TT ability) may suffer as a consequence.

If you want to aim for body fat loss with maximum muscle retention, research suggests maintaining a moderate-to-high amount of protein in your diet (1.5-2.5 grams of protein for every kg of your body weight). Most Australians already eat that much, so it doesn’t necessarily mean eating more protein, simply not cutting it back. If you’re willing to sacrifice muscle along the way for larger/faster weight loss then go for a low-to-moderate amount of protein (0.8-1.0 grams per kg body weight).

Another consideration for cyclists is how to fuel your training whilst losing weight. Carbohydrate is your main fuel source during moderate-to-vigorous exercise, but if you overly restrict it training intensity is likely to suffer. It’s difficult to put an exact figure on this because carb requirements vary with training volume and intensity, level of fitness, altitude and gender. But I’d suggest you only limit high carb foods if you have to, or where they’re also high in fat. You can also adjust the amount of carbs over the week to focus around bigger training days, with less on the rest and lighter days.

Translating this into food

So what does this mean in terms of breakfast, lunch and dinner? There’s no single answer to that – just like doing your tax return this is where you either have to sit down and work it out or call in an expert to help.

If you want to do it yourself there’s a variety of smartphone apps and websites that you can use to log your food and calculate the calories.  In Australia one of the best ones is Calorie King (www.calorieking.com.au). You don’t need to obsess about it but you probably need to at least have some idea of where the calories, fat, protein and carbs are coming from in your diet to make smart decisions about your eating. If your weight is currently stable then generally speaking a reduction of about 500 calories (or ~2000kJ) a day is required for weight loss of ~1kg a month. Faster weight loss comes with greater reductions, but this may be harder to sustain and fuel your training.

When deciding what to change in your diet, my advice is to be objective and forget any pre-conceived ideas about “good” and “bad” foods. Research shows that people who think this way are less likely to lose weight and more likely to regain it. Besides, if you can reduce your calories enough to lose weight and still eat a bag of chips every night, why feel guilty about it?

Instead be business-like and look at the numbers. Find the foods that contribute lots of calories, but ones that you don’t really care if you eat them or not. Don’t worry about haggling over the teaspoon of sugar in your coffee – it’s only 16 calories. If you can’t stand sugar-less coffee then why deprive yourself? There’s bound to be easier changes you can make. Remember you need to be consistently in negative energy balance for weeks, if not months, so it needs to be realistic and sustainable, without you feeling hungry or miserable.

There are some common mistakes I see when athletes try to lose weight:

  • - Eating large amounts of foods that are high in “healthy fats” such as avocado, oils, nuts and seeds. Whilst this is quite healthy from a cholesterol perspective, a gram of fat has the same calorie value no matter whether it’s from pig fat or olive oil. Half an avocado contains the same calories as a Mars Bar, and half a cup of raw almonds has more calories than 6 Weet Bix and milk!

 

  • - Snacking on sports bars, drinks and lollies when they’re not actually training. These foods pack a lot of energy into a small, easy to consume package. Not ideal for weight loss.

 

  • - Overeating protein shakes or other recovery foods when it’s not necessary (eg. after an easy recovery ride or an easy roll to the coffee shop with your mates)

 

  • - Not adjusting their calories for periods of lower training loads, or when you’re injured or taking a break from the bike

 

  • - Excessive calories coming from sports foods and supplements you don’t need

 

What happens if I restrict my energy too much or get too lean?

There are problems with restricting the energy in your diet too much, especially when coupled with large volumes of training. There isn’t space here to go into details (that could be another post) but the consequences can include:

  • - Fatigue and inability to perform to the level you should
  • - Menstrual cycle disruptions in females
  • - Loss of bone density in both men and women, due to hormonal changes in the – body
  • - Increased risk of illness and infection (including common colds as well as glandular fever)

 

Summary:

To lose weight you need to be in a consistent negative energy balance. Don’t assume because your diet is healthy that you’ll automatically lose weight, but on the flipside don’t feel that your eating has to be perfect either.

When choosing what to change in your diet try to reduce fat and alcohol first – if this isn’t sufficient you can try reducing carbs slightly, recognising that training intensity may suffer as a result. Avoid large reductions in protein unless your aim is to not only lose body fat but muscle as well. Vary your eating (especially carbs) depending on the amount and intensity of training, and be careful not to excessively restrict your diet for prolonged periods – it can have health consequences.

Finally be objective. Look at your diet and eliminate or substitute foods that you don’t care much about, rather than those you really look forward to. It’ll be easier and more sustainable in the long run.