At 2 p.m., the Miller sisters have just had their first meal of the day. Katy, a rankings analyst from Victoria University, and Amy, a civil servant, have already skipped breakfast and lunch, and they are packing their meal into a tight six-hour window.
Sharing a home in Lower Hutt, they had restricted their calorie intake over the years to try to lose weight and had tried all sorts of diets which had failed.
Amy says: “Diets always made me unhappy because I didn’t have enough calories and so my body went into panic mode.”
Katy spent her days thinking about the next meal. A year ago in February, she tipped the scales at 87 kilograms, was medically obese, with a BMI of 34, and was battling high blood pressure. Her doctor warned her that she was at risk of developing diabetes and suggested she try fasting – specifically, time-restricted eating, limiting her to eating within a narrow window.
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Amy weighed 107 kilograms, was 166cm tall and was also obese when the sisters started fasting – joining a growing number of people following what critics say is a bigoted (and dangerous) eating trend.
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The weight-loss strategy has been popularized in top-selling diet books and touted by celebrities, who regularly skip breakfast and eat all their meals between noon and around 8 p.m.
Fasting converts skip meals for 16 to 23 hours a day, while others follow different schedules: eat for five days, then fast for two, or follow the schedule of one meal a day. Proponents say the body uses stored fat and glucose for fuel, eating like we did in caveman times.
For those trying to lose weight, calories should be restricted. The dietary approach goes against traditional dietary advice – the idea that we should eat small amounts often and always eat breakfast.
Katy has lost 23 pounds, her blood sugar and blood pressure are back to normal. About 12 hours into a fast, she feels “a feeling of deep energy.” She can go without food for 20 hours or more and says, “I’m almost never hungry. I eat now because it’s time to eat and I no longer have any cravings.
Amy has lost 30 pounds.
They often eat Katy’s favorite dish for dinner – steak and mushrooms. The thing is, Katy says, they can eat whatever they want when they’re allowed to eat, although she’s stopped craving fatty foods like hot fries.
Food has become more and more precious at the same time. “I have no desire to go back to the way I ate before. I’m happy not to eat. I don’t know what I like best, to eat or not to eat.”
“My biggest concern about fasting is are you ready to do this for the rest of your life?”
Nikki Hart, a registered nutritionist in Auckland, has nothing positive to say about what she thinks is an influencer-led diet trend. She argues that fasting for health or weight reasons is not normal — but extreme eating behavior.
It can promote eating disorders, as it demonizes food and suggests restricting eating. “If you live in a family scenario, it’s not a good model. With all the issues we have with poor body confidence and eating disorders in our society, what behavior are you modeling would be my concern.
She sees two types of clients who come to her after trying and failing: middle-aged women who can’t eat as much as they used to, and “the group that joined the smoothie craze and no longer drinks. their smoothie until 10 a.m.
Those who fast miss at least one meal and possibly two, and possibly also nutrients such as whole grains. “Our lives are not made for fasting. We have long days and we are busy. The only fast I can understand is fasting for religious reasons.
“The problem if you pack everything you eat into one period is that you go into the binge/purge scenario. You’ve eaten all your food and that’s it for the day. We don’t just eat for function, we eat for social reasons, and I worry about the psychological impact of that.”
In the Wairarapa, Greig Rightford and his partner Mish McCormack help clients of their gyms who want to lose weight and advocate fasting for some of them.
Rightford says, “I would put someone on an intermittent fasting program rather than a calorie restricted diet because it’s so simple. You have nothing to do.”
Fasting makes people aware of what they eat rather than eating habitually, which helps those trying to lose weight. It also lowers insulin and resets hunger hormones.
“So many people are pleasure seekers who drink too much coffee and wine and rich processed foods. Fasting is a way to break eating habits, like you don’t need that chocolate muffin for morning tea,” he says.
Rightford – co-owner of Healthfit Collective – has been fasting occasionally for four years, but has times when he doesn’t fast, such as if he wants to build muscle or train for an event. He usually eats in a six to 10 hour window and also tried the 5:2 fast and went without food for three days.
“People can almost get high on it when they start feeling hungry because they can feel more focused.”
He worries, however, about obsessive followers, such as triathletes, bodybuilders and ultra-athletes who do not approach fasting with balance. And anyone with an eating disorder or an unhealthy approach to food shouldn’t be fasting.
Some of his clients have lost weight through fasting. But the research is mixed on whether this is a long-term weight loss strategy.
A year-long study of people who ate a low-calorie diet between 8 a.m. and 4 p.m., or ate the same number of calories at any time of the day, found there was no difference between whether a person has blocked all their food in one period or not.
Published in the New England Journal of Medicine, it included 139 obese people. Women ate 1200-1500 calories per day and men ate 1500-1800 calories per day. There was no significant difference in the amounts of weight lost with either dieting strategy.
Dr. Ethan Weiss, a food researcher at the University of California, San Francisco, told The New York Times, “There’s no benefit to eating within a narrow window.”
Another critical study, published in 2019 in Jama Internal Medicine, found that overweight adults during a 16-hour fast lost only 1 to 1.5 kilograms, and most of it was lean muscle mass.
In rural Waikato, Sarah Kull, a registered nurse and fasting specialist, says intermittent fasting has helped thousands of her clients lose weight and keep it off.
Kull began working with obese and diabetic clients four years ago who came to see her trying to lose weight. She advocates one meal a day for obese clients to really burn fat and says she gets them to a normal BMI.
“What we’ve done with modern diets is snacking between meals, which raises insulin. Fasting for eight to 10 hours overnight isn’t enough because your body isn’t able to process food, insulin never drops low enough at night and you wake up with higher insulin the next day.
“Having done this for four years now, I can absolutely say the weight loss is sustainable because [fasting] is a long-term lifestyle. People feel so good that they don’t stop.”
Kull is also a convert. She only eats in a four hour window – a lasagna and salad, fruit and crackers, usually having lunch and a late afternoon snack. When we speak at 5 p.m., the mother of two has finished eating for the day. “But I never miss social occasions, I just move my eating window around accordingly.”
But fasting is reserved for those who are generally healthy and is not suitable for people with eating disorders, children, adolescents, pregnant or breastfeeding women or frail elderly people.
There are “absolutely faster ways to lose weight,” she points out.
“Other diets may be just as effective, but they ultimately fail in the long run.”