Nutrition for weight loss

Fad diets don’t work but what to do instead? Jamie McGregor provides a scientific guide to creating and maintaining a healthy, goal-orientated eating regime.

Hands up if you have ever tried a juice detox, a high-fat diet or gone gluten-free? We get a lot of fad diets presented to us but many of them are unsustainable over a long period of time and, while some of them bring on dramatic changes quickly, they can simply be damaging. Most diets promise fast weight loss but what sort of weight are we losing? Others say results can be achieved by limiting calories but what type of calories do we need to keep tabs on?

What is it that good diets are trying to achieve? If your goal is to maintain a long-term healthy diet, it’s time to focus on the macronutrients – and how to balance them.

The science of eating

All basic diets are made up of a mixture of carbs, fats and proteins. These are the macronutrients, also known as macros. Each group can be assigned calorie values and then proportioned according to your goals.

On a basic level, we can view carbs as the body’s main energy supply. Although there are a few different energy sources, it is mainly carbs that give muscles the fuel they need to contract. Proteins are the body’s building blocks. Different types of amino acids link together to make protein chains and give cells their various structures. Fats, meanwhile, help with vital nutrient uptake, as well as providing insulation for cells and organs. They are also used as a back-up energy source to carbs.

In general terms, for normal healthy living, carbs should make up 45-65% of our diet. This percentage may seem overly high, as carbs are often vilified, but we need to consider the quality of the carbs we ingest. For instance, fruit, green vegetables, nuts and legumes are better carbohydrate sources than pasta, potatoes, or white rice.

Protein should account for 20-35% of our diet. Protein is used for muscle repair, so if you are exercising intensely and breaking down lots of muscle then your body will require large amounts of protein to repair itself.

Aim for a diet made up of 20-35% fat but be careful as to how fats affect your cholesterol levels. Polyunsaturated or monounsaturated fats are a better choice than saturated and trans-fats.

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Macros for goals

If you want to get serious about your diet, the science of eating is demonstrated best by those in the know – nutritionists. A good nutritionist will help you devise an eating plan that is in step with your goals. Things like meal frequency, content, variations, intolerances, metabolic rate, training regime, training goals and food preference are all carefully considered and tailored down to the last detail.

The tricky part is working out how much you should eat of each of the macro groups. Firstly, it’s important to note that different people have different tolerances to different macronutrients. As an example, ectomorph (naturally skinny) people are likely to have a higher tolerance to carbs than endomorph people, who have naturally broad shoulders and hips. Mesomorphs, the muscular, athletic-looking types, have a medium tolerance for carbs.

To lose weight, ectomorphs should follow a diet that is 25% protein, 55% carbs and 20% fat. Mesomorphs: 30% protein, 40% carbs and 30% fat. And endomorphs: 35% protein, 25% carbs and 40% fat. In balancing our macros, we also have to consider our daily activity levels and the quality of exercise we do. If you are in a sedentary job, you are going to have far different energy needs than someone who is physically active all day.

Now consider that our bodies are adaptive and therefore as we train and eat well, they change. Our energy needs and lean muscle content change over time as well. So while following a strict percentage rule will give you a good indication of how to balance your diet, according to your goals, it may not be entirely accurate. Taking weekly measurements (your girth at the calf, waist, tricep etc.) and readings (weight, fat content etc.) is a little time consuming but will give you a better picture of how your energy requirements are changing. Online macro calculators are extremely helpful if you go down this road.

You are what you eat

Last but not least, we need to consider the quality of the macros that we are feeding on. Is 200 grams of deep-fried white bread going to give you the same carb quality as 200 grams of quinoa?

If you are loading up on simple carbs (highly processed white bread for example) instead of complex carbs (say sweet potato), your body won’t be able to turn them into energy as efficiently. The same goes for your proteins, as they need to come from good lean sources. Eat some fresh turkey breast as opposed to a Big Mac.

Fat intake is probably the trickiest to get right and there is still a stigma attached to fats. Foods like avocado, nuts and egg (yolks) are all good monounsaturated fat sources. Look to seeds, fish oil and salmon for your essential supply of Omega 3 fatty acids.

If you are looking to lose weight, and maintain your ideal weight, having a relevant and progressive exercise regime is a great start but you need to back it up with a structured nutrition regime.

Identifying your energy requirements is the most important thing, as these are constantly changing. Then you need to work out how to divide your energy requirements into the correct macronutrient groups according to your goals. All this requires a lot of persistence and attention to detail but hey, so do squats.

Jamie McGregor is a personal trainer with Perun Fitness, which runs classes in Tung Chung and South Lantau. You can call him on 6443 6597 or visit www.perunfitness.com.

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