Lack of energy is the inability to carry on with activities smoothly or becoming less productive. Nutrition experts say that the type and quantity of food a person eats, plays an important role in determining their energy levels during the day.

Even though all foods give energy, some foods contain nutrients that could help increase the energy levels and maintain one’s alertness and focus throughout the day.

Encyclopedia of Agriculture and Food Systems 2014, defines food energy as the energy released from carbohydrates, fats, proteins, and other organic compounds. When the three major calorigenic nutrients (carbohydrates, fats, and proteins) in a food are burnt entirely with sufficient amounts of oxygen, it releases energy or food calories that are expressed in kilojoules (kJ) or kilocalories (kcal).

Dieudonne Bukaba, a nutrition expert at Avega Clinic Remera, is of the view that yoghurt may be a source of energy. For instance, natural yoghurt is rich in protein, fats, and simple carbohydrates. This provides energy to the body.

He says, "Sweet potatoes and yams are essential sources of carbohydrates, which provide energy. Sweet potatoes are also high in fibre, which may help slow the body’s absorption of these carbohydrates. This may make them a good option for sustained energy throughout the day.”

He adds that nuts are also usually high in essential fatty acids. As a study in the Journal of Parenteral and Enteral Nutrition notes, these fatty acids may help reduce inflammation, which may also lower fatigue. However, since nuts are high in calories, people should be careful not to eat too many.

According to Healthline, brown rice is a very nutritious food. Compared to white rice, it’s less processed and retains more nutritional value in the form of fibre, vitamins, and minerals.

One-half cup (50 grams) of brown rice contains two grams of fibre and provides a large portion of recommended daily intake of manganese, a mineral that helps enzymes break down carbs and proteins to generate energy.

Medical News Today explains that all food provides the body with energy, however, the energy can vary greatly. Some foods, such as sugars and refined carbs, give the body a quick jolt of energy. However, more often, the body needs more sustainable energy from ingredients such as fruits, grains, and legumes.

A study in Critical Reviews in Food Science and Nutrition notes that avocados are healthy fruits rich in nutrients and contain proteins, and fibre that may help sustain energy levels throughout the day. They also contain good fats that may increase energy levels, and make fat-soluble nutrients more available in the body.

A study in the Journal of Agricultural and Food Chemistry notes, strawberries are a good source of minerals, vitamin C, and folates. They also contain phenols, which are vital antioxidants that may help the body create energy at the cellular level.

Oranges are known to contain Vitamin C that may help reduce oxidative stress in the body and prevent stress. A study in the Journal Antioxidants states that young adult male students who have higher levels of vitamin C may also have better moods and may be less likely to experience confusion, anger, or depression.

Bukaba also points out that seeds, such as pumpkin seeds, chia seeds, are rich sources of fatty acids and fibre, more energy. 

According to the World Health Organization, energy intake (calories) should be in balance with energy expenditure. To avoid unhealthy weight gain, total fat should not exceed 30 per cent of total energy intake. Intake of saturated fats should be less than 10 per cent of total energy intake, and intake of trans-fats less than one per cent of total energy intake, with a shift in fat consumption away from saturated fats and trans-fats to unsaturated fats and towards the goal of eliminating industrially-produced trans-fats.

Bukaba warns against feeding on fast foods or fried foods, added sugars, packaged snacks and baked sweets such as cakes and sugary pastries, however, urges everyone to choose a diversified diet containing numerous nutritious foods that give the body sustained energy.