Calorie Distribution

Not only does eating more earlier in the day (morning and afternoon) provide well-timed energy to get through the day, but it also increases the likelihood of eating enough vitamins and minerals that we need for proper body functioning. Research suggests that eating more of the day’s total energy intake earlier in the day is associated with a lower risk of excess weight, increased ability to meet vitamin and mineral recommendations, and make it less likely to develop risk factors for cardiovascular disease (risk factors include high LDL cholesterol, low HDL cholesterol and high blood pressure), compared to eating most of our calories later in the day (afternoon and evening).

This is partly because eating earlier in the day has been linked with a reduction in the amount of added sugar eaten throughout the day. There is also an association between eating breakfast and lower risk of developing cardiometabolic risk factors like high levels of LDL cholesterol (bad cholesterol) and low HDL cholesterol (good cholesterol), impaired glucose metabolism, and elevated blood pressure. Skipping breakfast has also been found to increase LDL cholesterol, and an increased risk of developing type 2 diabetes. Although there is some debate over skipping breakfast, and fasting regiments may be appropriate in preventing diabetes and cholesterol problems too.

Fasting and eating windows

Intermittent fasting is the intake of energy within strictly defined times within a day or week. Current research is still somewhat controversial. Some studies have shown mild weight loss when following time restricted intake patterns, lower fasting glucose and insulin resistance in generally healthy adults, as well as decreases in LDL cholesterol and blood triglycerides in studies that were of short duration. Other studies have shown that time restricted eating is not effective in weight loss compared to eating throughout the day.

The time of day that you eat may also make a difference based on our circadian rhythm. If you are fasting (and even if you are not), eating earlier in the day may help support weight loss (Source).

Alternative day fasting (ADF) is gaining traction. ADF involves eating very little (e.g. less than 500 calories) one day and then eating whatever you want the next day. This pattern repeats. A one year long study comparing ADF with calorie restriction (eating 75% of your calorie target daily) and a third group that ate whatever they wanted. The calorie restriction group was similar to ADF but better in one way: the ADF had worse LDL (bad) cholesterol. It was also harder to follow an ADF diet (Source). The takeaway: calorie restriction is likely a good approach for weight loss and metabolic disease. For longevity, there could be benefit to the occasional longer fasting period, but that is another conversation.

What this likely means is more, high quality, long term research is still needed to fully understand the long term effects. There are also negative side effects that can be experienced such as dizziness and fatigue, and there are certain situations where this type of diet pattern can be dangerous (eg: reactive hypoglycemia). Therefore it is important to discuss the appropriateness of intermittent fasting with your health care provider.