There’s no shortage of diet plans promising to melt away the pounds by calling for strict proportions of protein, carbohydrate and fat.
But, according to a new study, it doesn’t matter where the calories come from. What matters most for shedding body fat is simply eating fewer calories – and sticking to your plan, be it high protein, low carb or low fat.
Some, but not all, studies have demonstrated that high protein, low carbohydrate diets work better than others at losing fat and preserving muscle mass over the short term.
There’s also debate over which diets, if any, are most effective for reducing visceral fat, deep abdominal fat that’s closely related to the harmful metabolic effects of obesity. Visceral fat packs itself around the organs and secretes chemicals that increase the body’s resistance to the hormone insulin and cause inflammation throughout the body.
The current study – called the Pounds Lost trial – set out to determine whether the composition of a weight loss diet affected the loss of lean muscle, total body fat, abdominal fat, visceral fat or liver fat in 424 overweight or obese men and women. (Excess visceral fat is thought to release fat into the bloodstream causing a build-up of fat in the liver.)
Participants were assigned to one of four diets: 1) low fat (20 per cent daily calories), average protein (15 per cent); 2) low fat (20 per cent), high protein (25 per cent); 3) high fat (40 per cent), average protein (15 per cent); or 4) high fat (40 per cent), high protein (25 per cent).
Each diet was low in saturated fat and cholesterol and high in fibre, included low glycemic carbohydrates and was designed to cut 750 calories a day. All participants were offered group and individual counselling sessions over two years.
Body fat and muscle mass was measured using CT (computed tomography) scanning after six months and two years of follow up.
At the six-month mark, participants had lost, on average, more than nine pounds of total body fat along with five pounds of lean muscle, but had regained some of this after two years. Fat loss or muscle loss did not differ between the four diet groups.
As well, the proportion of protein, carbohydrate or fat in the diet did not affect the amount of abdominal fat, visceral fat or liver fat that was lost during the study. After six months, participants shed about 40 per cent of visceral fat and 60 per cent of liver fat.
At the two-year follow-up, people were able to maintain a weight loss of more nine pounds, including three pounds of abdominal fat.
The bottom line: The major factor for weight loss was adherence to a calorie-reduced diet, not the proportion of carbohydrate, protein or fat it contained. People who followed their diets better lost more weight and body fat than those who didn’t.
These findings strongly suggest you’re better off choosing a plan that’s easy to stick to over the long haul – provided, of course, it’s a healthy diet.
An earlier report from the Pounds Lost trial revealed that all four diets were heart-healthy regardless of their protein, carbohydrate and fat content. Each diet reduced levels of triglycerides (blood fats), LDL (bad) cholesterol, lowered blood pressure and increased HDL (good) cholesterol.
That said, most people in weight loss programs gradually revert to their previous diets over time even if they do manage to maintain some fat loss.
If your 2012 goal is to shed excess body fat, the following tips will help you adhere to a healthy diet plan and increase the likelihood of success.
Plan in advance
It’s the most common blunder that steers people off-track: not being organized. On the weekend, spend a few minutes thinking about the week ahead. Map out your meals, healthy snacks and even your workouts.