Carbs, Cardio and Fat Loss.
To promote fat loss, do you have to stop eating carbohydrates?
The most asked question of a personal trainer?
How do I lose weight?
In the 80’s, the trainer would have said with confidence “reduce your dietary fat to no more than 10% of caloric intake”.
The 90’s trainer would have said, “exercise more and stop eating so much, especially fat”.
The trainer in the 2000’s would tell you it’s not actually dietary fat that makes you fat, it’s a conspiracy – it’s the carbohydrate. Stop eating it, especially at night. And don’t eat it at lunch or breakfast, just to be sure.
The trainer over the last few years would say, “don’t eat any carbohydrate, don’t do any aerobic exercise, take this, this and these, three times a day”.
Does the struggle with losing weight most people experience some time or another in their lifetime or the ever-expanding waist line of our nation indicate that experts really have no clue about the subject matter? Could so many weight loss researchers be so wrong?
It may come as a surprise, but the answer to the first question is extremely straightforward. The biology of weight loss is very, very well understood. On the other hand, the psychology of losing weight, and keeping it off, is not. The question is not “how do I lose weight?” Frankly, that is the easy part. The hard part is how to keep the weight from creeping back after 6 months.
Despite all the confusion on this topic, you cannot lose weight until an energy deficit is created. That is the major point. Everything else are the details.
Should I exercise? Should I reduce carbohydrate? Cut out fructose? Turn my back on sugar? These questions are subordinate to the primary two-pronged questions: (1) How can we reduce your energy intake to below what you need (or increase energy expenditure, or both – ideally) and (2) how can we do this in a way that you find sustainable and, dare I say, enjoyable?
The other question that I believe is often overlooked – especially with the popularity of intermittent fasting protocols, such as the 5:2 diet, is (3) how can we do the above whilst maintaining muscle tissue?
Studies show “weight” lost in response to diet or diet and exercise is always a mixed of muscle mass and fat tissue. I think everyone agrees that the goal should be reduction in fat mass while preserving lean tissue. And this is not easy.
It is 2016. Our understanding of weight loss has come a long way. Are we still talking about not eating carbohydrate to lose fat? Are we only concerned about “weight loss” and not body composition?
Lets look at a very recent study just published by Professor Hawley’s group in Melbourne, conducted by Ev Parr. Before we do, just remember how very, very difficult (and expensive) it is to perform long-term nutrition research. Providing food, training, counselling, with all the blood tests and body composition scans. Hats of to the Hawley group for pulling off a study like this.
What did they do?
The researchers examined the effects of 16-week varied dietary protocols with exercise on body composition in overweight or obese men and women. The three groups studied were (1) high-dairy protein, moderate-carbohydrate diet, (2) high-dairy protein, high carbohydrate, and (3) low dairy protein, high carbohydrate.
The details of each group were:
* High dairy protein, moderate carbohydrate (40% CHO: 30% protein: 30% fat); * High dairy protein, high CHO (55%: 30%: 15%); or
* Control (55% CHO: 15% protein: 30% fat).
Energy restriction was around 500kcal/day and was achieved through diet (~250 kcal/day) and exercise (~250 kcal/day). Body composition was measured using dual-energy X-ray absorptiometry before, midway, and upon completion of the intervention.
What did they find?
Eighty-nine of 115 participants completed the 16-week intervention, losing 7.7 kg fat mass and gaining 0.5 kg lean mass.
What was the interesting discovery?
There was no difference in the changes in body composition (fat mass or lean mass) between groups.
What did they conclude?
Compared to a healthy control diet, energy-restricted high-protein diets containing different proportions of fat and carbohydrate confer no advantage to weight loss or change in body composition in the presence of an appropriate exercise stimulus.
What does this mean to us?
1. We only lose weight when a caloric deficit is created;
2. Even modest caloric deficits result in meaningful weight loss – this study created only a 500kcal/day deficit;
3. The macronutrient composition of the diet is subordinate to the energy deficit created. Thus creating dietary plans that are sustainable and enjoyable really is the most important factor. If the diet is too restrictive, the diet is doomed to failure. Don’t repeat this glaring mistake made by billions of others who start a diet only to give it up 3 weeks later because it was “too hard to follow”;
4. Exercise is a ‘must’. Not only does exercise add to the caloric expenditure but it also sensitizes the muscle to carbohydrate, assisting with fat loss;
5. The protein content of the diet and the addition of strength training, most likely, become more important at protecting muscle loss when the deficits are much larger (i.e. over 1000kcals a day). This remains to be determined but this is what we have found using DXA as our measurement of body composition.
Article by Tony Boutagy.