To lose fat long term, change the way you think about the journey and don't over-restrict, ex-Royal Navy physical trainer and personal trainer Iain Reitze told Insider.
Most of his clients want to lose weight, and while Reitze doesn't have a problem with that he tries to shift their focus to improving their performance and health.
When you focus on eating well and exercising for your health, your body's appearance changes as a by-product, he said.
"I try to change the mindset and get the focus off weight loss because there's a lot of emotional attachment and stigma that comes with gaining or losing weight," he said.
Reitze — who joined the Royal Navy at 16 and became a physical training instructor, working with new recruits, special forces from NATO, inmates in military prisons, and injured servicemen and women undergoing rehab — believes his military background has helped him develop the skills needed to adapt his style for each person.
Reitze left the Navy after 27 years and now runs fitness retreats in Portugal and the UK. He believes people should strive for a balanced lifestyle, meaning both regular exercise and a little bit of what they fancy, such as a couple of glasses of wine at the weekend.
Many nutrition and fitness professionals share this approach, advocating the "80/20 principle" that encourages making nutritious food choices 80% of the time and enjoying what you want the rest of the time. Cutting out food groups and over-restricting is unsustainable for most people so does not generally lead to long-term success.
That doesn't mean you shouldn't push yourself, though. Reitze said one of the best things about the military is that it shows people they can do things they think they can't, which builds confidence.
Fat loss comes down to being in a calorie deficit. To achieve it you need to be both consistent and persistent, and nail the following points, Reitze said.
Before you do anything, it's important to write down exactly what your goal is and set an ideal time-frame for achieving it, as this will make you reflect on how disciplined you're willing to be, Reitze said.
For example, if you want to lose 10 pounds in five weeks, most people will likely have to be relatively disciplined and stay on track most of the time. However, if you gave yourself 10 weeks to lose the same amount, you would be able to eat more and indulge in treats while hitting your target.
Research suggests that slow weight loss is the most sustainable.
It's important not to overhaul your whole lifestyle in one go, Reitze said.
For example, if you want to drink less, cut down on but don't cut out alcohol, and then gradually reduce your consumption, Reitze said. This stops it from feeling overwhelming.
Experts agree and the same goes for fitness — if you don't exercise at all, the chances are you won't be able to stick to five workouts a week if you don't build up gradually.
Whether dropping your calories too low and eating too little or cutting out food groups and things you enjoy, overly-restrictive diets generally aren't sustainable.
If your diet makes your life miserable, you may end up resenting your goal, Reitze said.
By including all foods you enjoy in moderation and eating enough so that you're losing weight but still have energy, you will enjoy the journey, he said.
Remember you're in control of your thoughts: Don't tell yourself you can't eat something, tell yourself you're choosing not to, Reitze said.
He likens it to how many people make the conscious decision not to smoke, even though we all could.
Instead of saying you "have" to go to the gym, tell yourself you "get" to. Coaches agree that changing your mindset is an important part of fat loss success.