© Camila Goodis

Intermittent fasting has soared in popularity in recent years.

While the concept - usually practised by "fasting" for 16 hours overnight and shortening your daily window of food consumption to eight hours - has been scientifically linked to numerous health benefits, the majority of people do it because they want to lose weight.

However, a celebrity personal trainer told Insider she thinks it's a bad strategy for fat loss.

Camila Goodis - known as the "Brazilian body wizard" - believes the key to sustainable weight loss is eating six times a day, so a meal or snack every two to three hours.

"There is no human being that can be doing this [intermittent fasting] for their whole life," she told Insider. "Your body needs the normal. Eat when you're hungry, right? You don't want to starve yourself."

Goodis is a certified pilates instructor, personal trainer, and lifestyle consultant who has trained a host of celebrities including Sofia Vergara, Robbie Williams, and many others that she can't disclose due to NDAs.

Most recently she's been widely heralded as the person responsible for Adele's dramatic transformation. However, Goodis clarified to Insider that although she has trained Adele in the past, she hasn't seen the singer in seven years.

© Goodis advocates a mix of pilates and strength-training.

For her clients, Goodis recommends eating little and often - she herself eats seven times a day sometimes.

"You're constantly eating. But it's small quantities and whole foods," she said.

"So once you eat every two hours or every three hours, you're never hungry because you're constantly fueling. Your body is like a gasoline, like your car, right? If you don't put gas in your car, your car is not going to go. Our body works the same."

Goodis believes eating often helps those trying to lose weight stay in a calorie deficit because they know their next feed is never far away, so smaller portions are easier to enjoy.

"They eat small, but they know that in two hours they're going to eat again and be like, 'okay, that's not that bad,'" she said.

This is one of the reasons Goodis believes you should avoid eating out as much as possible if you're trying to lose weight - restaurant food tends to be extra calorific because there's often lots of oil and butter added which, although delicious, can ramp up the calories drastically without you realizing.

"I don't care how healthy the restaurant is, you don't know how this food is cooked," she said. "They put a lot of salt and oil in the food, so I don't trust any restaurant. If you're on a real diet, I don't trust any restaurant besides my kitchen."

© Camila Goodis

When it comes to losing fat, Goodis believes it's 90% down to diet and nutrition, and that you don't even have to go to the gym if you don't want to.

"If you follow your diet, go for a little walk three times a week, you will lose weight," she said.

And on the flipside, even if you're training multiple times a week in the gym, if you're overeating - even "healthy" foods - you won't lose weight, according to Goodis.

"Everything is portion control," Goodis said, adding that she recommends people start measuring their foods if they've never done it before so they know how much they're eating.

Gaining muscle, strength, and sculpting a "toned" physique, however, is a different matter, and that definitely requires exercise - Goodis favours a mixture of strength-training and pilates.

Related video: Jennifer Aniston says she's on the 16:8 intermittent fasting diet—but what is that? [via Health]