The calorie conundrum
The old idea is that it was just about eating less calories. More and more studies show that eating a low glycemic load (GL) diet, designed to keep blood sugar level even, causes more weight loss on the same calories than a conventional low-fat, low calorie diet.
There are two ways of eating low GL. One is by having very little carbs. Since you have to eat something that means lots of protein and/or fat instead. The other is to eat less carbs (and consequently a bit more protein) but choose the right kind of slow-release low GL/GI carbs – whole rather than refined. Both work. A low GL diet is also more effective for treating and preventing Type 2 diabetes.
But calories do count and one of the extra advantages of eating a low GL diet is that it reduces hunger – and if you’re not hungry you eat less. This is because sugar makes your blood sugar go up, which leads to weight gain, then down, which leads to carb cravings. Somewhere along this rocky road insulin levels rise, this is the hormone that is released when we eat carbs and stores them away as fat for a rainy day. The more ‘insulin resistant’ we become, the more we have to produce to control blood sugar.
Is insulin control the key to weight loss?
High insulin is thought to be a consequence of diabetes and obesity, but animal studies suggest it might be the other way around with high insulin driving obesity. Animals with the same diet but high or low insulin levels don’t end up the same weight. High insulin animals gain much more weight when given a high fat, calorie diet. 
There are a lot of reasons to think that controlling your insulin level is a vital key, not only to weight loss but also weight maintenance. In my 100% Health Club newsletters we’ve explored the ground-breaking research that shows that reducing insulin switches on anti-ageing genes and ‘skinny’ genes, an effect that is annihilated by giving experimental animals a tiny bit of sugar.
You may recall that animals (and humans) fed very low calories are obviously skinnier, but also show all the signs of living longer. Insulin appears to be the key, not calories, for switching on these health promoting genes which supercharge your metabolism.
A case in point are two studies by Dr Michelle Harvie and Professor Tony Howell, which resulted in their book The Two Day Diet. Seduced by the animal research which showed positive gene switching when animals were given low calories every other day, they experimented with giving people a low calorie diet (600kcals) twice a week, compared to a regular low calorie diet.  The 2 day diet worked a bit better, delivering 14lbs weight loss in 26 weeks compared to 12lbs on the conventional low calorie diet.
But then they repeated the experiment, not focussing so much on calories on the two ‘down’ days but more on avoiding carbs with lots of protein and fat – a kind of part-time Atkins diet. They got a comparatively better result – nearly 9lb weight loss in 12 weeks versus 5.3lbs on the conventional low calorie diet. 
Actually, neither results are that impressive but these experiments do illustrate two points: first that you don’t necessarily need to eat less every day to lose weight, which might make diets easier to stick to, and secondly that controlling insulin with a low GL diet seems to work better than just eating fewer calories.
The dangers of high protein diets
One of the problems I have with high protein/low carb diets such as this is that they are invariably achieved by eating tons of meat and dairy products.
Variations on the Atkins diet, with high protein and fat and low carbs, have consistently been shown to be effective for short-term weight loss, but not good for maintenance/long-term weight loss. Measures of cardiovascular risk improve, as do diabetes.
Depending on the quantity of protein consumption there is an increased risk of kidney failure and reducing bone mass, contributing to osteoporosis. High meat and/or dairy diets are also associated with increased risk of cancer, especially breast, prostate and colorectal cancer. The World Health Organisation , the World cancer Research Fund and the American Inssisute for Cancer Research all agree on this. An article review on meat, dairy and cancer in the American Journal of Clinical Nutrition confirms that the link, especially with colon cancer, is convincing.
Also, while dairy products are low GL they do raise an insulin hormone called IGF-1 (insulin-like growth factor) which is known to increases cancer risk and may switch off some of the anti-ageing benefits.
My favourite Low GL diet approach
For these reasons I have favoured a low GL diet based on eating a little more protein, mainly from fish and vegetable proteins such as beans, lentils, nuts and seeds, and less carbs as well as focussing on the low GL carbs such as wholegrain pasta, oat flakes, brown rice, quinoa and other such foods.
In head-to-head trials this kind of low GL diet has proven just as effective in losing weight short-term as Atkins-type diets but is clearly better in the long-term. An example of this is the Diogenes (Diet, Obesity, and Genes) study which was designed to assess the efficacy of diets that varied in their protein content and GL, in the prevention of weight regain. In this trial, the group maintained on the low GL diet with moderately higher protein (25% of calories from protein) had the highest compliance, the lowest dropout rate, and was the only group that did not regain weight by the end of the 26-week weight maintenance intervention period.  This is my kind of diet.
Also, according to a study we did on a group of patients supplied by a GP practice, the weight loss is substantial with an average of 14lbs in 12 weeks, coupled with extremely positive changes in all the usual vital statistics, with reduction in cholesterol, blood fats (triglycerides), blood pressure and blood sugar. 
I compare this to a medical practice which advocates a low-carb approach and also provides group support. They have reported 20lbs over 15 months. Good, but not nearly as good as my low GL diet results.
This is the diet that I advocate in my Low GL Diet Bible and Low GL Diet Cookbook and is delivered through my weight loss groups called zest4life, which operate throughout the UK and Ireland (see www.zest4life.com for details).
Alternate Day Dieting and Intermittent Fasting
While my kind of low GL diet is highly effective for weight loss, more so than conventional low calorie diets, is there an advantage to varying what you eat from day to day?
The concept of ‘alternate day dieting’ and ‘intermittent fasting’ came out of animal studies that showed a lot of the same benefits seen in animals eating low calories if the animals just ate less every other day. This caught on after BBC Horizon’s programme presented by Michael Mosley, who has since authored the Fast Diet based on eating less two days a week, with a Mediterranean style diet in between. Why Michael Mosley chose two days is a bit of a mystery since the most effective trials have all involved three alternate days. While two days might seem more doable there’s no evidence yet that it works.
Dr Monica Klempel, from the University of Illinois, has pioneered much of this research and reported a 12lb weight loss in 8 weeks (1.5lbs a week) on alternate day low calorie dieting, with a low fat diet in between. 
One of the most impressive results was shown in another 8 week trial giving people 25-30% less than their calorific needs for three alternate days by Dr Samira Eschghinia in Iran.  This showed a 13.2lb weight loss.
However, given that it appears to be lowering insulin that is the primary mechanism for the benefit of alternate day dieting, I favour alternate days based not only on low calorie but on low GL. Based on the calorie difference needed between the ‘fast’ and ‘feast’ days I estimate that the best weight loss result is likely to be achieved by having a diet with 35 GLs on the ‘fast’ days, with no more than about 800kcals on average, and 50 GLs on the ‘feast’ days.
The total GLs in a given week is not greatly different to my low GL diet (45 GLs average a day). This Alternate-Day Low-GL Diet is not difficult to do. It means having three 10GL meals and one 5 GL snack. This way of eating naturally reduces appetite on the ‘feast’ days so, once again, 50 GLs is ample if you choose the right kind of foods. Exactly how to do this is explained in my book Burn Fat Fast.
Is diet plus exercise the winning formula?
Further research at the University of Illinois, headed by Surabhi Bhutani, has tested the effect of either alternate day dieting, or exercise, or both combined. Exercise alone was not that effective but, combined with the alternate day diet, doubled the weight loss from 6.6lbs in 12 weeks to 13.2lbs. 
But what kind of exercise makes a difference? The convention is that the longer you are exercising the better, with the primary goal being to burn calories. But this, much like conventional calorie theory, is proving to be far too simplistic.
Based on clear results in animal studies, short bursts of high intensity exercise, is as effective as long exercise sessions, as this study illustrates. Professor Martin Gibala from the McMaster University in Canada had one group of students ride a stationary bike for 90 to 120 minutes. Another group did what’s called high intensity interval training (HIIT), which involved a 30 second burst of sprinting, by cycling as fast as they could, then resting for a couple of minutes, then sprinting again, repeating the cycle 4 to 6 times. So, this second group clocked up 2 to 3 minutes of intense exercise in a 6 to 8 minute training session. Both groups exercised three times a week.
So, who do you think were fitter, and more able to burn fat, at the end of the experiment? They had almost identical benefits on all tests. The difference was that one group had exercised for five hours in the week, and the other for about 9 minutes!
What about in the long-term? The general view from many studies of exercise is that, for both all-round health and fitness, but also for weight burning, you need a balance between muscle-building exercise, called ‘resistance’ or strength training and ‘aerobic’ or endurance exercise. That might mean a ‘strength’ session of alternate days and a 30 minute endurance exercise, such as a jog, brisk walk, cycle or swim.
Given the clear advantages of ‘interval’ training this kind of short burst high intensity exercise can either be built into your ‘strength’ training routine or endurance session. For example, I had Kate Staples, former Gladiator (Zodiac) and expert personal trainer devise me an 8 minute every other day routine to achieve this, which is now part of my Burn Fat Fast routine. Together with an Alternate Day Low-GL Diet I estimate that it will produce a weight loss of 14lbs in 8 weeks.
The Fibre Factor
One of the main factors that determines whether a carbohydrate food is high or low GL is the amount and kind of fibre it contains. Soluble fibres, as found in oats and chia seeds, absorb water and, as a consequence, make foods such as chia porridge absorb more water and make you feel fuller. Apples and beans also contain soluble fibres which are known to stabilise blood sugar and result in less insulin release.
The king of soluble fibres is glucomannan fibre, found in the Japanese konjac plant. Glucomannan has consistently been shown to help weight loss. In North America one of the best-selling weightloss supplements is a highly soluble fibre supplement containing glucomannan called PGX®. Both glucomannan and PGX are either taken as a powder in a 5 gram serving, or as three capsules before meals, always with a large glass of water. 5 grams of this fibre absorb about one litre of water. At this dose it helps you lose weight. Taken three times a day this means about 3 litres more ‘bulk’ in the stomach and intestines, making you feel much fuller. PGX has been extensively researched and is well established to both lower the GL of a meal, reduce the need for insulin, and also both reduce hunger and promote a feeling of satiety after a meal. 
Taking glucomannan or PGX with a large glass of water immediately before breakfast or a main meal makes it easy to not need snacks in between meals because one’s blood sugar levels stay even for much longer. For those wishing to experiment with my suggested Alternate-Day Low-GL Diet the addition of a pre-meal super fibre supplement makes a lot of sense.
There are a number of dietary supplements that assist weight loss and help to keep insulin levels down. One of my favourites is chromium, which is an essential nutrient used by the body for the proper function of insulin receptors. It is poor insulin reception that leads to insulin resistance that means the body has to produce more insulin. For example, in one study  healthy, overweight women who experienced carbohydrate cravings were given either chromium or a placebo for eight weeks. Those on chromium ate less, felt less hungry, craved fat less and also lost more weight than those taking the placebos.
Other supplements that have been shown to support normal blood sugar and insulin regulation and have been shown to assist weight loss are HCA (an extract from tamarind), 5-HTP (a form of tryptophan) and CLA (conjugated linolenic acid). Cinnamon extract, while not proven to cause weight loss, also helps stabilise blood sugar levels.
My favourites, based on the evidence, are chromium, HCA and 5-HTP.  Please note that 5-HTP is not recommended if you are on antidepressant drugs in which case I recommend the combination of chromium with a cinnamon extract.
Some supplements contain combinations of the above, where you take one capsule/tablet just before each meal.
In summary, the best and healthiest way to lose weight, and keep it off, is a combination of the following:
• A low GL diet (45 GLs to lose weight, 60 GLs to maintain)
• Three alternate ‘fast’ days on lower GL/calories – a total of 35 GLs/800 kcals and other days on approximately 50 GLs.
• 3-5 grams of glucomannan fibre or PGX before each meal, with a large glass of water.
• Supplement HCA, chromium and 5-HTP, plus the basics of a high potency multivitamin, extra vitamin C and essential fats.
• Alternating resistance and endurance exercises. Resistance exercises can be done in an 8 minute sequence involving four exercises that use different groups of muscles. Endurance exercise can be done in half an hour, including short thirty second bursts of high intensity exercise, eg sprinting, four to six times during your training session.
Exactly how to do all this is explained in my new book with exercise expert Kate Staples, called Burn Fat Fast.