A new year often heralds the start of a new resolution to overcome the excesses of the festive season. Eating well is one of the first steps many of us take for better health at the beginning of the year, says Jean Hailes for Women's Health dietitian Stephanie Pirotta, but that often becomes wrapped up in confusion around calories, nutrition and restricting what we eat to lose weight.
Jean Hailes clinicians never encourage specific diets; instead, it's about balanced, healthy eating. But with so much talk at the moment around various diets that encourage fasting in some form — such as the 5:2 Diet and the 16:8 — it's important to look at the health realities of the practice, says Ms Pirotta.
Put simply, fasting involve consuming few or no calories over a particular time period. One of the most popular ways of fasting is intermittent fasting, which is low or no calorie consumption for a defined number of hours or days (e.g. 18-48 hours) during certain days of the week. Over an average week this might involve having the recommended number of calories five days a week, and reducing calorie intake to 25-40% of the recommended amount, two days a week. For women, that's usually around 500-800 calories a day (as a guide, half a medium avocado is around 150 calories). Alternatively, periodic fasting involves constant low-calorie consumption; around 750-1100 calories a day over a longer duration (e.g. 2-21 days).
Does fasting work? In a recent U.S annual review of 16 studies on intermittent fasting, 11 of these studies reported weight loss. Only two found significant weight loss in those following some type of fasting plan, however. "For some people, intermittent fasting can lead to weight loss because it improves a person's overall eating habits and reduces their daily energy intake," says Ms Pirotta. "It can also lead to a decrease in 'bad' cholesterol and insulin levels, which can help manage or reduce the risk of chronic diseases such as type 2 diabetes and cardiovascular disease."
Of course, there are still drawbacks. Fasting may lead to fatigue, headaches and constipation and it's not recommended for the elderly, frail, pregnant women and people with diabetes. There's also always the possibility that some people might overeat on their non-fasting days, which can prevent weight loss over time. "Larger and longer-running human trials are needed to confirm the impact of intermittent fasting on health," says Ms Pirotta.
Intermittent fasting for no longer than 48 hours can improve the metabolism and the body's ability to burn fat, says Ms Pirotta. This is what helps reduce weight. However, longer periods of energy restriction can lower your metabolism to conserve your energy. "This is commonly what leads to weight regain when starting to eat regularly again after following a low energy diet for a long period of time," says Ms Pirotta.
"There's still very little evidence to show that intermittent fasting is any more beneficial that a daily calorie-restriction plan in the long term. It's best to follow an eating plan that works best for you and your lifestyle, so that it's realistic and will be effective," she says.
"Before considering any type of eating plan, I would urge women to see an accredited practising dietitian or their GP. Talk about your health needs and your lifestyle to come up with a plan that suits you."
Created by Jean Hailes for Women's Health naturopath, Sandra Villella.
Red lentil tomato capsicum soup (130 calories per serve)
Serves: 6 (note: portion sizes are important)
Prep: 10 mins
Cooking: 35 mins
This story and recipe can be reproduced for free on the condition that Jean Hailes is credited as the content provided. Or, contact us if you'd like to interview Jean Hailes dietitian Stephanie Pirotta for your own story. Stephanie is available during the festive season. Please contact Janelle Carrigan on 0409 939 920 or email [email protected]