You know that low-GI (Glycaemic Index) foods are better for keeping your blood glucose levels in check, but what you may not realise is that GI is also important when it comes to losing weight. Far from cutting out carbohydrates, which only makes you crave them more, losing weight the low-GI way is about choosing ‘smart’ carbs – those that are slowly digested and absorbed, keeping you fuller for longer and making it easier to burn fat.
What is GI?
The brainchild of Jennie Brand-Miller, the University of Sydney’s internationally renowned Professor of Human Nutrition, the Glycaemic Index is a means of measuring the rate at which the body absorbs carbohydrate in food and raises blood glucose levels (BGL).Some foods, such as processed breakfast cereals, instant rice and packaged snack foods, flood your bloodstream with glucose so rapidly they give you an instant energy rush, which fades away just as fast to leave you feeling flat and hungry by midmorning. These are high GI foods. The blood glucose spikes they cause can result in health problems, especially if you have diabetes.Other foods, most typically those that come to us in a more natural state (such as traditional oats, many fruits and vegetables, dense and grainy breads, milk and legumes) qualify as low GI. This is because your body digests them relatively slowly, releasing a gradual but steady supply of glucose into your bloodstream. The result is sustained energy, fewer hunger pangs and more stable BGLs. This brings major long-term benefits. By reducing insulin requirements, you’re less likely to store fat. Keeping your BGLs within the healthy 4mmol/L to 7mmol/L range reduces your risk of diabetes complications. Testing your blood regularly will keep you in touch with how well you are travelling.
How does it work?
One of the hardest things about losing weight is being hungry – when your tummy’s rumbling, it’s hard not to overeat and it’s more difficult to resist temptation. Yet to lose weight, you need to take in fewer kilojoules, which means cutting down on what you’re eating now. Research shows that carbohydrate foods with a low GI are better at filling us up than higher GI alternatives. In fact, a review of 16 studies found that low-GI foods increased feelings of fullness, delayed the return of hunger or reduced voluntary food intake in 15 of those studies. Another benefit of low-GI foods is that, like exercise, they lower your body’s need for insulin – the body’s main fat-storing hormone. There is evidence to suggest that eating low-GI foods can help us burn more fat by keeping blood glucose and insulin levels lower. Studies have shown better weight loss on lower GI diets.
In one study, people with diabetes who reduced the GI of their diet by 25 per cent lost an average of 7.7kg. Losing weight the low-GI way doesn’t mean choosing just any low-GI foods, or eating them to your heart’s content – not all low-GI foods are healthy. Chocolate, for example, is low GI only because its high fat content means it is digested slowly. Potatoes, on the other hand, are high GI but are packed with nutrients, so it is fine to eat them in moderate amounts. Watching your fat and sugar intake, filling up on fibre and keeping your eye on portions all still apply. But add to this a focus on choosing low-GI carbs and you will boost your chances of success.
Putting it into practice
Everyone’s dietary needs are different, and your daily kilojoule intake is governed by factors such as your age, sex, height and weight. While a dietitian can help you with a weight-loss plan tailored to your personal needs, adopting the principles of low-GI eating will boost your efforts by staving off hunger pangs, keeping your blood glucose levels down and boosting your energy levels.
This really is the most important meal of the day when it comes to losing weight. Research shows that those who eat breakfast regularly are less likely to be overweight, while skipping it can worsen insulin levels and blood fats and lead to weight gain. Eating breakfast gives you better energy levels and concentration during the day, and stops you snacking on high-fat foods later.
Step 1: Choose high-fibre cereal based on oats and barley, or heavy wholegrain breads such as Bürgen, Vogel’s and Tip Top 9 Grain. (Portion suggestion: ½ cup muesli or oats, or 1 cup flaked cereal, or 2 slices bread.)
Step 2: Add protein. Try eggs, salt-reduced baked beans, canned fish in springwater, low-fat milk or yoghurt, low-fat ricotta or cottage cheese, and nuts or nut spreads. (Portion suggestion: 1 egg, or 95g can fish, or 130g can baked beans, or 1 cup milk or 200g yoghurt, or ½ cup ricotta or cottage cheese, or 30g raw nuts or 2 tablespoons nut spread.)
Step 3: Add fruit or vegetables for fibre, anti-oxidants and vitamins. Try fresh fruit or tinned fruit in natural juices, berries, mushrooms, grilled tomatoes, spinach or capsicum. (Portion suggestion: ½-1 cup fresh fruit or cooked vegetables.)
Consider these satisfying combos:
- Wholegrain toast with natural almond spread and sliced banana.
- Bowl of low-GI cereal (try Kellogg’s Guardian or Sustain or Goodness Superfoods Digestive 1st, Protein 1st or Heart 1st) with milk and berries.
- Fruit salad with yoghurt and a sprinkle of natural muesli.
- Toasted rye sourdough with ricotta and grilled tomato.
- Baked beans on Tip Top 9 Grain English Muffins.
Taking a break for a satisfying lunchtime meal is important for maintaining energy levels and concentration. It will also prevent hunger and excessive snacking during the afternoon and before dinner. Whether you’re eating at home, taking lunch with you or eating out, there are plenty of healthy choices available.
Step 1: Pick your low-GI carbs. Good choices include wholegrain bread or a roll, Ryvita crispbreads, noodles or pasta, cracked wheat, quinoa and legumes. (Portion suggestion: 2 slices wholegrain bread, or 4 Ryvita crispreads, or 1 cup cooked noodles or pasta, or 2⁄3 cup barley or cracked wheat, or ½ cup cooked quinoa, or 1 cup cooked or canned legumes.)
Step 2: Add a little lean protein. Good choices include canned fish in springwater, eggs, lean chicken or turkey, leftover cold meat, marinated tofu, low-fat yoghurt, low-fat ricotta or cottage cheese and legumes. Avoid processed and smoked meats and fish, which are high in salt and have been linked with an increased risk of type 2 diabetes and cancer. (Portion suggestion: 1 egg, or 95g can fish, or 50g lean meat or chicken or tofu, or ½ cup ricotta or cottage cheese, or ½ cup cooked or canned legumes.)
Step 3: Add a good serve of vegetables or salad. (Portion suggestion: 1-3 cups.)
The options are endless, but here are a few ideas to get you started:
- Wholegrain sandwich with salmon and salad.
- Vietnamese rice-paper rolls filled with tofu or prawns and vegetables.
- Vegetable frittata, made with sweet potato, capsicum, peas and corn.
- Bowl of minestrone or lentil and vegetable soup (preferably homemade).
- Toasted sourdough with ricotta and roasted vegetables (try capsicum, eggplant, zucchini and pumpkin).
7 steps to losing weight the low-GI way
1. Eat at least five serves of vegetables and two serves of fruit a day.
2. Opt for wholegrain breads, cereals and grains with a low GI.
3. Be choosy about fats – obtain yours from healthy sources such as olive oil, nuts, seeds, avocado and oily fish.
4. Consume more legumes, such as lentils, chickpeas or dried beans.
5. Include more fish and seafood in your diet, particularly oily fish such as salmon and sardines.
6. Go for lean cuts of meat and poultry. Avoid processed meats.
7. Choose low-fat dairy products or soy products.