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.
If scheduling a week's worth of meals seems overwhelming, plan for only one or two days in advance. Planning ahead means you'll be less likely to give in to temptation.
Learn to say no. Whether that means turning down sweets at the office or asking a server to hold the buttery sauce, being assertive will get you closer to your goal. Changing your eating habits is within your power; nobody else is going to do it for you.
Chart your progress
The more monitoring you do – and feedback you get – the better you'll do. Keep a daily food and exercise diary. Track your weight weekly and your body measurements monthly (e.g. waist, hips, chest). Charting progress provides awareness, focus and motivation.
Don't expect to be perfect – there are bound to be a few glitches along the way. Make change easier by listing potential obstacles – junk food in the house, grocery shopping on an empty stomach, skipping breakfast and so on. Identifying trouble spots makes it easier to avoid them.
Consider lapses as momentary setbacks, not the ruin of all your hard work. All-or-nothing thinking is a detriment to success. If you allow yourself to lapse occasionally, rather than beating yourself up, you'll be much more likely to pick up where you left off.
Don't hold off on congratulating yourself until you reach your final weight goal. Every small success deserves at pat on the back. Rewarding yourself as you meet interim goals is a way to remind yourself that you can do it.
Follow up with yourself
Once you've reached your goal, don't get smug. Just because your clothes feel great, or your cholesterol is in the healthy range, doesn't mean you can get away with second helpings or an extra dessert each week. It's a slippery slope that will lead you back to your starting point.
For a detailed breakdown of the meal plans for each of the four diets studied, visit: www.nhlbi.nih.gov/health/public/heart/other/pounds_lost_1400.htm.
Leslie Beck, a Toronto-based dietitian at the Medcan Clinic, is on CTV's Canada AM every Wednesday. Her website is lesliebeck.com.