January is diet month and this is National Obesity Awareness Week, so a perfect time for the British Nutrition Foundation’s symposium on popular diets. I like to make sure I am convinced by the science before I recommend any weight management system, so I couldn’t wait to hear the latest insights from key researchers on the 5:2 diet, low GI diet, high protein low carb diets, Palaeolithic diets, and more. 
We know that you get significant health benefits from losing just 5% of your body weight, and that miracle diets offering speedy and massive weight loss are doomed to failure. But let’s face it, the mantra of eating a sensible varied diet is dull, and one size doesn’t fit all. So the evidence behind popular diets needs to be considered and each one is part of a toolset that dietitians can use to suit the individual; different people will require different strategies that fit with their culture and lifestyle habits.
My take-outs from the day:
- Research on intermittent fasting shows that it helps to reduce insulin levels in a matter of days. This can improve your sensitivity to insulin, helping to reduce your risks of diabetes.
- There are many variations to the fasting method of dieting, such as alternate day fasting, and feast on 5 days fast on 2 days. The books on the 5:2 diets aren’t necessarily a true reflection of the research and you can’t just extrapolate from the research by creating a different intermittent fasting plan and expect the same good results. The published evidence is based on fasting for 2 consecutive days (e.g. milk, fruit and veg, 600kcal) followed by five days on a Mediterranean eating plan. That approach for the 5 days makes good sense to me.
- Research time and time again substantiates the value of low glycaemic diets and better blood sugar control. Fact.
- There is some evidence on the effect of low GI foods on appetite, satiety and weight loss. High GI diets have been linked to higher insulin levels and overeating.
- Palaeolithic diets are based on what we were eating in the Stone Age but adapted to modern day habits. They are rich in plant foods – and a huge variety. These foods tend to be low in energy density (fewer calories per gram).
- Research on high protein low carb diets suggests that this way of eating slows the rate of passage through the small intestine, which facilitates a feeling of fullness.
- There’s good evidence on the value of controlled very low calorie diets in reducing symptoms of psoriasis, knee osteo-arthritis and sleep apnoea.
In the end, we need to remember the basic message of energy in energy out – if you eat fewer calories than you burn, you will lose weight. Period. I believe it is possible for you to lose and keep the weight off with the right approach and support.
More info on BNF events.
