A popular diet myth that has been around for many years and keeps raising its head is the “high protein/low carbohydrate diet”, Atkins. Recently popularised by celebrities such as Jennifer Aniston, it quickly became the UK’s number one bestseller.
As a nutritionist, I’m constantly asked the question about my view of the Atkins diet and being very opinionated as usual I’m often quite prepared to give it. To say the least my view is “controversial” – meaning open to discussion. However, in order to understand the problems with Atkins it is important to examine the basis of a healthy diet.
The basis of a healthy diet
One of the problems we face publicly is the word diet itself. Most people associate the word diet with a reduced calorie intake, (a weight loss plan). In the fitness world of course the word diet encompasses all eating, and the words weight loss refer to fat loss. This aside, when we consider any weight loss plan, we should all be looking for a balanced healthy approach. For any diet to be considered healthy it should follow these guidelines.
- cause a small energy deficit (for weight loss this should be no more than 500 kcals than the need. ACSM 2000)
- be balanced across all the food groups
- come from a varied nutrient source
- contain food of a high quality (as unrefined as possible with as much fresh food as possible).
It should not:
- recommend cutting out any food group
- reduce kilocalories below 500 less than the person needs
- mean buying special foods
- claim any weight loss in excess of one or two pounds per week
- be prescriptive in only eating certain foods at certain times.
The atkins diet and where it fits
For many individuals who are suffering from excess weight the quick fix solution is a “dream”, and as with all dreams we often pursue them rigorously only to be disappointed. The ideal body for one in two individuals in the UK is becoming a dream, as 52% of women and 48% of men are already overweight, not to mention the problem we now have with one in three children suffering from weight problems. Can diets such as the Atkins diet curb this trend? One of the most important tools for anyone is to be able to evaluate it for themselves. Does it follow the healthy diet guidelines?
A permanent way of eating that:
- lets you lose weight without counting calories
- makes you feel and look better
- naturally re-energises you
- keeps lost pounds off forever.
Ask yourself the question: do people lose weight on the Atkins diet? I know many people who have claimed to, and when they do, experience many of the above statements. Why?
Atkins bases these claims on physiological “pseudo-science” which, to a point, is a great pity as some of the recommendations are useful education tools; eg, highlighting the different types of carbohydrates that exist. The pseudo-science that Atkins claims is that most obesity is caused by the body’s metabolism being disturbed and that this disturbance is from eating too many carbohydrates leading to insulin resistance and hyperinsulinism. The solution, Atkins suggests, is to control carbohydrate intake and eat less refined carbohydrates thus avoiding the foods that cause you to be fat.
In my view the claim of this disturbance has no scientific basis, however, the solution of controlling less refined carbohydrates can have an effect on insulin levels.
Insulin plays two major roles in the body: it reduces blood sugar when blood sugar is elevated beyond normal levels (ie, after feeding on carbohydrates) and it may reduce liploysis (the release and breakdown of fat from the fat cells).
In brief, many highly refined carbohydrates have a high number of kilocalories packed into a small amount of food (high density) and respond in the body the same way as sugar. If blood sugar is dramatically elevated then insulin will respond and can often cause a “hypo-glycemic” back-lash by lowering the blood sugar too quickly or too low. This will normalise within an hour to an hour and a half, but in the meantime may trigger hunger again. The idea of limiting highly refined carbohydrates therefore does not seem unreasonable.
The Atkins diet, however, while making these claims to do so, doesn’t limit to acceptable levels of refined carbohydrate, it actually encourages reduction of carbohydrate to such a low level that it would be considered by nutritionists as having been eliminated, particularly in phase one. We would strongly oppose this suggestion as carbohydrate is not only our primary energy source but it is also impossible to use fat as an efficient fuel without the presence of carbohydrate.
To gain first hand information on the effects of the hypo-calorie restriction we asked one willing participant to test the diet for us and monitor her feelings.
Phase one: the induction phase
The claim in this phase is to switch your body’s metabolism from a carbohydrate-burning to a fat-burning system. However, this is not physiologically possible, as I have stated previously, without the presence of some carbohydrate, fat cannot break down and fuel the body.
In phase one, carbohydrate is reduced to only 20g, which equates to approximately 80kcals. While carbohydrate is low, fat intake is likely to increase and this would be equally damaging for health and weight loss. The saving grace of this phase is that it is only for two weeks. This could not be carried on long term.
Our tester, who followed this phase religiously, started to feel weak after the second day but by the end of the week still felt energised.
Phase two: ongoing weight loss phase
Again in this phase the claims are based on physiological pseudo-science. Carbohydrate intake can now increase but only by 5g now amounting to 25g = 100kcal. This is still too low for energy production.
Our tester felt throughout this stage that her energy levels were fine but found chocolate cravings and constipation levels were increasing and her weight loss had slowed down.
In the first week most of the weight loss would be water. Carbohydrate takes into storage three times its weight in water which could make you 4-5lbs heavier on the scales when carb stores are full. Emptying the carb stores in the first week gives a false impression of weight loss and an appearance of a slowing down of weight loss at a later stage. The constipation that Louise was experiencing would be due to lack of fibre and nutrients.
Phase three: pre-maintenance and lifetime maintenance
This phase increases your carbohydrate intake in increments of 5gms or 10gms per week as long as you continue to lose weight to a critical carbohydrate level for maintenance (CCLM). The carbohydrate foods listed to choose from in these phases are all good fibrous sources of carb with vitamins and minerals. However, the amount is still too low as they recommend increases up to between 40g-90g per day for a heavy exerciser. Louise continued to struggle with constipation, felt her hunger was under control although her energy levels were weak.
The weight loss issue
Our Tester’s Results
- Week 1 – 3lbs
- Week 2 – 2lbs
- Week 3 – 2lbs
- Week 4 – 1lb
Total Inches Lost
- Chest – 1.6
- Arms – 0.7
- Waist – 4.3
- Hips – 2.4
- Legs – 0.7
Overall Louise was very pleased with the weight loss, but since coming off the regime has put on half the weight she lost.
The weight loss undoubtedly came from a lack of kilocalories, which would happen on any kilocalorie restricted diet. Psychologically the diet is easy to follow as you can eat as much as you like of protein and fat foods. Once carbohydrate is recommended (phase 3) the foods from which you can choose carbohydrate are all good sources of non-refined carbohydrates.
My recommendations would be to change the message to allow non-restriction of the carbohydrates that are recommended in the lists as they are low density kilocalories of carbohydrate and even with no restriction people are not likely to take on board excess calories. This would be a similar recommendation to healthy eating. People would also be less likely to replace the missing calories with fat which should be kept within balanced levels (no more than 30% of calorie intake). Also encourage refined carbohydrate (white bread, rice and pasta) to be a reduced part of the diet but not totally restricted therefore not causing deprivation.
As for phase one! If only followed for a week and makes you feel good, who knows? This phase long term, definitely not!
Long-term research is being undertaken on the Atkins diet over a period of five years in the US. Watch this space!