Best time for main meal of the day?
A 2004 study (1) found that we are likely to feel the most satisfied from food eaten in the morning, and that this satisfaction grows progressively weaker throughout the day. This means it is good to eat a big breakfast, because it will give you a feeling of satiation (feeling full) for a larger part of the day. If you under-eat during the first part of your day then you're likely to more than make up the calories during the latter part of the day.
If you want to lose weight or even just to hold steady, the study shows that it may be best to eat your largest meal in the morning, followed by a midsize lunch, and a small dinner. The researchers propose that your daily circadian and diurnal rhythms may be the cause of this effect.
Another research project (2) found that obese people who ate a large 600-calorie breakfast with healthy protein and carbohydrates lost significantly more weight than those who ate only half as much breakfast. The researchers speculated that eating a large balanced meal in the morning keeps blood-sugar levels steady during the day, keeping food cravings at bay.
However, one in three adults in France, Italy and Spain skip breakfast completely. They are not overweight, are generally healthy, and may not have much to eat until early afternoon. A number of studies done after the above two find that there is no association between skipping breakfast and obesity, insulin or glucose problems, or appetite control. (3, 4, 5)
Your body type does have a clear influence on your circadian rhythms, and thus whether you are a morning person or an evening person. The best advice is to gravitate towards what suits you. With the exception of just-before-bed meals, what you eat, and how much you eat, is more important than when you eat.
I personally like to have breakfast and really enjoy it, because I have a swim in the cold ocean every morning, and that uses up a lot of calories. I usually have a ketogenic (no carb) breakfast and hot cup of black coffee and it feels wonderful. It is usually a pile of fried green vegetables, a couple of eggs, mushrooms or seafood in butter.
Some people find they cannot cope with a large breakfast, finding it too "heavy". In Grow Youthful I discuss some interesting research that explains why a ketogenic breakfast may be the most healthy and rejuvenating approach to meal times.
1. The time of day of food intake influences overall intake in humans. De Castro, J. M., Journal
of Nutrition 2004 Jan;134(1):104-111.
2. Effect of diet with high carbohydrate and protein breakfast on weight loss and appetite in obese women with metabolic syndrome. Jakubowicz, D. et al.; Endocrine Society Annual Meeting, poster session, June 17, 2008.
3. Brown AW, Bohan Brown MM, Allison DB. Belief beyond the evidence: using the proposed effect of breakfast on obesity to show 2 practices that distort scientific evidence. Am J Clin Nutr. 2013 Nov;98(5):1298-308. doi: 10.3945/ajcn.113.064410. Epub 4 September 2013.
4. James A Betts, Judith D Richardson, Enhad A Chowdhury, Geoffrey D Holman, Kostas Tsintzas, Dylan Thompson. The causal role of breakfast in energy balance and health: a randomized controlled trial in lean adults. Am J Clin Nutr (4 June 2014);100(2): 539-47.
5. de la Hunty A, Gibson S, Ashwell M. Does regular breakfast cereal consumption help children and adolescents stay slimmer? A systematic review and meta-analysis. Obes Facts. 2013;6(1):70-85.